An illustrated catalogue of Rudolf Sturany’s type specimens in the Naturhistorisches Museum Wien, Austria (NHMW): deep-sea Eastern Mediterranean molluscs

The “Pola” expeditions were the first to explore the deep Eastern Mediterranean Sea in the 1890s. They remained the most intense surveys in that area for a century and constitute today a fundamental baseline to assess change in the basin, whose fauna is still inadequately described. Solid taxonomic foundations for the study of deep-sea organisms are needed and we here contribute by revising the name-bearing types of mollusc species introduced by Rudolf Sturany on the basis of the “Pola” material from the Eastern Mediterranean Sea stored in the Natural History Museum in Vienna. Sturany introduced 15 names (Marginella occulta var. minor Sturany, 1896 shall not be considered as the introduction of a new name). He described and established two manuscript names by Monterosato: Jujubinus igneus and Pseudomurex ruderatus. The genus Isorropodon was also introduced together with its type species I. perplexum. For each name, we list the available type material, provide the original description and a translation into English and illustrate the specimens in colour and with SEM imaging.


Introduction
The second half of the 19 th century was an exciting period for marine exploration: most of the seafaring nations of the time sent out expeditions to investigate the sea. The Austro-Hungarian monarchy did likewise, planning a geographically restricted but intense series of expeditions to the Eastern Mediterranean and the Red Sea (Schefbeck 1996). These expeditions were the joint effort of the important research institutions of the time: The Imperial Academy of Sciences (now the Austrian Academy of Sciences), the Imperial and following text) (ICZN 1999). Some names were termed as varieties of other species. Whenever Sturany clearly clarified the intention of introducing a new name, such names are considered to be of subspecific rank following the article 45.6.4 of the ICZN Code. A taxon list in alphabetical order with page and figure numbers in this paper is provided in Table 1. Any citation to the International Code of Zoological Nomenclature (ICZN 1999) should be considered to its online version which includes all recent amendments.
For each species, we provide references to the original description and figure, the original localities, a list of the type material, the original description and its translation into English. All inventory numbers provided refer to the Mollusca collection of NHMW. The systematic arrangement follows Bouchet and Rocroi (2005) and Bouchet et al. (2010) for gastropods and bivalves, respectively. The reassessment of the current taxonomic status of Sturany's names is beyond the scope of this paper and we relied on the published literature to add comments in this regard. The expeditions surveyed several localities in Greece and Croatia ( Fig. 1) whose names were stated in Italian; in our translation, we also use the modern Greek and Croatian names ( Table 2).
The NHMW hosts a large collection by Monterosato that was a fundamental reference for Sturany to identify his material. This collection was purchased in 1889, just the year when Sturany started to volunteer in the mollusc collection. The acquisition from December 1889 reads: "Shells of the Mediterranean Sea ca. 2082 sp.-collection of the zoologist Monterosato, purchased for 500 fl. Ö.W." [translated]. In 1897, Sturany -now assistant of the collection -wrote the complete inventory: 2113 inventory numbers altogether. Unfortunately, hardly any of the original labels are preserved within this collection nor is the original list, but Sturany had apparently transcribed all names very carefully.
Some names had been written on labels but never formally described by Monterosato. Such manuscript names have either been described by Sturany (e.g., Jujubinus igneus) or rendered available by redescription and illustration (e.g., Pseudomurex ruderatus).
Photos were mostly shot with a Nikon SMZ25 microscope; large shells were photographed with a Canon 350D camera, a 50 mm lens and extension tubes. SEM images were taken with a JEOL JSM-6610LV, using low vacuum without any coating. Specimen measurements have been added for holotypes. The map in Fig. 1 was drawn with the oceanmap package (Bauer 2017) in the statistical programming environment R, version 3.3.3 (R Core Team 2017).
The three specimens at hand are approximately 7.5 mm high and 5.7 -6 mm wide. The uppermost of the 8 -9 whorls are pink, the others are pastel olive green with pink and bright yellow marks or lines. The spiral cords consist of tubercled rows and rough horizontal stripes in-between. There are five spiral cords counting from the penultimate whorl up to the protoconch. There is hardly any prominent varix above the suture which is a typical feature in Tr. exasperatus Penn. Seven concentrically blended yellow and rose spotted cords frame the covered umbilicus. Moreover, close to the keel of the last whorl there are one to two unspotted cords. Here on the bottom of the shell, the lateral cords are tighter and finer than those visible on the whorls.
Overall, this description matches the specimens described by March. Monterosato as Jujubinus igneus in the collection of the Hofmuseum (Imperial Museum of Natural History), therefore I chose this name. Only the livelier red colour (receding of the olive green colour and prevailing of yellow and pinkish) and the here bright red and yellow spotted, prominent sutural varix are important characters. Comments. Sturany identified these shells by comparison to specimens in the Monterosato collection (NHMW 27441) which closely match the specimens found in the "Pola" expedition ( Fig. 2 A-F). However, Monterosato never formally introduced the name. Therefore, the variety igneus has to be considered a new subspecific name introduced by Sturany following the provisions of art. 45.6.4 of the ICZN code. This name is considered a junior synonym of Jujubinus exasperatus (Pennant, 1777) (MolluscaBase 2017). The name Trochus (Jujubinus) igneus was used also by Brusina (1896), whose work postdates Sturany's one because he explicitly mentioned the preprint of Sturany's work, and later by Locard (1904 fig. 13).

Translation. From station 194 (160 m).
The single specimen of this new species shows only 5 ½ whorls, as the apex is missing from the shell. Each whorl has 10 prominent axial ribs which are not developed equally, but some here and there are remarkably thick and high, surrounded by others smaller than average. In between the ribs and covering them are numerous (more than 20) spiral threads, which look like small grooves under the microscope (Fig. 4). Small pits ornament the threads. They seem to be crossing points of the spiral threads with axial lines which are no longer visible in our specimen (in this regard compare the microsculpture of Scaria funiculata Watson).
In contrast to closely related species, the ribs sink into the deep suture in a curved manner, not angled. However, they form a keel around the umbilicus through the thick interconnections of their lower ends. A thick varix is present on the lip and makes it seem duplicated.
The shell is 5 mm high, 2.2 mm wide and the diameter of the mouth is 1 mm. Translation. From station 243 (103 m); 1 specimen.
The shell is 31 ½ mm high and 16 mm wide. A deformation led to doubled development of the siphonal canal. The original siphonal canal is pointed towards the left and forms a deep, umbilicus-resembling funnel, while it is overtopped in length by the secondary siphonal canal to the right.
The mouth opens into the siphonal canal, whose margins never touch each other, is continuously open and 15 ½ mm long. The apex is slightly damaged, seven whorls are preserved.
The sculpture of the whorls resembles those of the coralliophilas; it is accompanied by a number of spiral cords covered unevenly with scales. On the top whorls, there are 3 to 5 such formations which are even and strong (broad) and show only few scales. On the last two whorls, we find considerably more, which alternate quite regularly between stronger (broader) and weaker (narrower) formations. One narrow, scale covered cord is periodically found after two strong spiral stripes. On the last whorls there are varices which are slightly less prominent on the top whorls. The lip is toothed, corresponding to the spiral stripes ending there.
The specimen is too large to be Coralliophila squamulosa Phil. (Kobelt,Prodr. p. 15;Carus,Prodr. p. 380) and it has only nine lateral folds on the last whorl, while that species supposedly has 12 to 13. Perhaps though, Mr. March. Monterosato was looking at similar forms when he decided to attribute Coralliophila squamulosa as a variety of Murex brocchi, resp. Fusus craticulatus (Monterosato, Nuova Rivista, p. 39).
One specimen of 45.5 mm length and 18.5 mm greatest width; the mouth is 9 mm wide and 28 mm long, 15 of which belong to the siphonal canal which is open on top. The apex of the shell is missing and only 6 whorls are preserved. A keel which is especially prominent on the lowest whorls runs in the lower half of the whorl and forms two flattened protuberances wherever it crosses the sparse axial ribs. Therefore, the number of these protuberances corresponds to the number of axial ribs, which is 6 at the body whorl and 8-9 at the spire whorls. A greater number of spiral cords run above and below the keel. They vary slightly in thickness, resembling those in Fusus rostratus, but without scales and are only poorly transversely ribbed. The suture is deep. The inside of the aperture is loosened above the columellar lip in an undulated callus which is perpendicular to the last whorl. The siphonal canal is bent.
At first appearance, the form described here could be mistaken for a variety of Fusus rostratus Oliv., however, this interpretation would not be justified, due to the centred, exorbitantly sharp protruding keel.
The gray brown shell is fusiform and has 6 ½ whorls, almost 4 of which belonging to the socalled protoconch. This shows, in some parts, a finely reticulated sculpture (Fig. 12), while on the lower 2 ½ whorls there is a completely different sculpture (Fig. 11). Below the suture lies a slender, concave part with many arched axial lines, which is followed by the remaining part of the whorl's width, separated by 1 or 2 spiral lines. This remaining part is convex and is provided with solid axial ribs (10 on the penultimate, 12 on the last whorl), crossed by rather strong spiral stripes (3 on the penultimate, 6 on the last whorl). The aperture is pearshaped with a small opening on the upper outer edge and is elongated downwards and blended into the siphonal canal, which is also ornamented by some spiral stripes.
The length of the shell is 3.5 mm, the width 2 mm, and the height of the aperture with the siphonal canal 2 mm.
In its form, this new species resembles Defrancia cordieri Payr. (Kobelt Prodr, p. 143), as well as its related forms for which Monterosato establishes the genus of Cordiera. It also shows multiple similarities to an unpublished species to date, Cordiera hispida Mont. in coll., which is available to me as an object of comparison from the museum collection. However, it seems that the characterization and distinction can be made sufficiently due to its smaller dimensions.  (Fig. 6), sowie von Station 213 alle mit Ausnahme jener zwei Exemplare rechnen, welche ich gleich bei der Besprechung der Gehäusebreite ausgenommen habe. Diese muss ich, da sie, wie gesagt, relativ breiter sind, und da sie ferner mehr Spiralrippen besitzen (nämlich circa eben so viel wie die echte nuperrima in der Monterosato-Collection des Hofmuseums) als Raphitoma nuperrima Tib. typ. isolieren (Fig. 5). Leider sind sie nicht erwachsen.
Translation. From stations 1, 36, 213 (597-680 m), one specimen from each of the first two stations and a larger number from the latter station.
The specimens of the Austrian deep-sea expedition fit the descriptions currently found in the literature rather well; however, they poorly match the available figures.
It shall be demonstrated that not all of the presented specimens belong to the type, and it is therefore necessary to give some information on the dimensions. Only one specimen reaches the size of 12 mm described in the literature as typical height, all the rest are of far smaller dimensions. Furthermore, with the exception of two specimens, they show a smaller shell not only in absolute terms but also in relation to the type which is available to me as an object of comparison, unfortunately in the form of a broken and juvenile specimen from the Monterosato collection. This type also shows a greater number of prominent spiral ribs and stripes on all whorls, while our specimens show only two ribs from the penultimate whorl upwards to the protoconch, which forms a slight edge, much as it is the case in Pleurotoma (Mangelia) acanthodes Wats. Our specimens also correspond completely with this species from the Bermuda Islands and Azores in dimensions, sculpture of the protoconch. Strictly speaking, there is no difference between our specimens and acanthodes Wats., except for its richer tubercled sculpture, i.e., between the spiral cords of the last whorl, there are much more rows of granulose structures than there are in acanthodes, and above the last rib of the last whorl, namely between it and the suture, there are 10 to 12 such cords. Because of that great similarity of the majority of the collected specimens with Watson's species, I would like to separate it from Raphitoma nuperrima Tib. as nov. var. pseudacanthodes and include the large specimen from Station 1 (Fig. 6), as well as all those retrieved from station 213 with the exemption of those 2 specimens which I excluded from the review of shell sizes. As mentioned above, I have to isolate them as Raphitoma nuperrima Tib. typ. (Fig. 5), because they are relatively broader and possess more spiral ribs (approximately as many as the real nuperrima in the Monterosato collection of the Imperial Museum). Unfortunately, they are juveniles.
Finally, also the specimen retrieved from station 36 must be designated a remarkable variety. It distinguishes itself by a greater gap between spiral ribs 1 and 2 on the last whorl and must be compared to a second species by Watson, Pleurotoma (Mangelia) corallina from the West Indies, which is why I mention it as nov. var. corallinoides (Fig. 7). Translation. From station 82 (2420 m); 1 specimen with incomplete aperture.

Comments
Light brown shell, fairly thick, consisting of 5 whorls. The protoconch (1 ½ whorls) has a somewhat rough surface, but no distinct sculpture. Quite suddenly, sharply pronounced axial ribbing appear at the second whorl and continue until the aperture. The axial ribs are embedded closely together and angled by a central spiral keel and, moreover, crossed by several spiral threads. Such threads, though pronounced only weakly, are already visible right beneath the suture; however, they are only well distinguishable on the last two whorls.

Europe PMC Funders Author Manuscripts
Europe PMC Funders Author Manuscripts Furthermore, at the body whorl there are 2 spiral stripes beneath the keel and 6 to 7 on the ultimate whorl between keel and umbilicus. As a result of the axial ribbing and spiral stripes, there is a network of slanted rectangles or squares with a hint of a granular sculpture here and there, which is only visible at higher magnification.
Each whorl is equipped with 22 to 26 of the previously mentioned axial ribs.
The unfortunately damaged aperture is pear shaped and has a leftwards rotated, short, nozzle-shaped siphon and a, likely also in the mature state, sharp outer edge. The columella is broadly lashed out towards the left and covers a scar-formed umbilicus almost completely.
Height of the shell 3.5, width 2, aperture height 1.7 mm. I am not entirely convinced that the present specimen is related to Taranis cirrata Brugn. (Kobelt Prodr., p. 137) and according to its origin must be placed within the north Atlantic genus Taranis. Perhaps this will be further discussed. It is smaller than Taranis cirrata and has one whorl less. Furthermore, a spiral stripe is distinctly pronounced as a keel, while the other fainter ones recede. On the whole, probably only the number of spiral lines concur in both forms, whether they appear as a keel or only ring-formed, and also the number of axial ribs seems to be the same as in Taranis cirrata, however, we see important differences in the aforementioned traits and especially in the shaping of the columella.

Translation. From station 82 (2420 m).
There is only one right valve of 13 mm in length, 6.7 mm in height and 3.2 mm in width (thickness), as well as a left valve of a remarkably smaller (approximately only half the size) specimen (length 6.8, height 3.5 mm). The shells are nearly monochrome yellow, except for the umbo which stands out whitish, and shine lightly of mother-of-pearl on the inside. The concentric stripes on the outside are slightly irregular, as single stripes stand out more prominent. The umbo is moved far to the front, within the first fifth or sixth of the shell. The rear upper margin is shaped completely straight until its rounded transition into the posterior margin. Being built significantly higher at the posterior than at the anterior, the shell in its outline has roughly the shape of Modiola (Gregariella) sulcata Risso. The axial sketchy lining at the hinge margin, which makes it appear as a set with a large number of smaller, vertically and tightly arranged teeth, caused me to place this very peculiarly shaped new bivalve within the exotic genus Myrina. The large right valve shows smeared tracks of these teeth-like lines only here and there, while they are clearly visible under higher magnification in the left valve of the second specimen. Here, the axial lines are not limited to the posterior part of the hinge plate, but are also visible directly beneath the umbo on a tooth-like structure, approximately at the position of the beginning of the anterior upper margin, very similar to Myrina coppingeri Wats from northern Australia, depicted in the Challenger work (E. Smith, Lamellibr., pl. XVI, fig. 9).
In spite of the mentioned hinge characters, the belonging of the described bivalve to the genus Myrina is no less than evident and the last word has certainly not been spoken yet. Das Schloss stimmt vollständig mit dem von L. spinifera überein, und auch der Wirbel ist wie dort glatt und nach vorne und innen geneigt. Die Farbe ist nahezu rein weiß, die Wölbung der Schale eine schwache. Die Länge der Schale beträgt 11, die Höhe 9,5 mm.

Comments. A valid species placed in genus Idas
Translation. From station 82 (2420 m); one right valve.
At a first glance, the shell at hand seems to be perhaps a deformed specimen belonging to Lucina spinifera Mont. (Kobelt Prodr.p. 369;Carus Prodr. p. 152), but is after all clearly distinguished regarding the following points: 1. The lunula, in this case, is a narrow but deep cavity, therefore the outline of the shell is quite a different one than in Lucina spinifera. 2. At the boundary between ventral and posterior margin, a broad, cornered cove cuts deep into the shell and continues radially as a concavity (similar to the genus Axinus) further to the middle of the shell height. On the inside of the shell, this depression corresponds to a bulbous thickening from the outside. 3. The number of concentric ridges, which are fainter and stand closer together than in L. spinifera, amounts to approximately 66 (compared to about 40 in L. spinifera). 4. The posterior upper margin runs from the umbo back-and downwards in a slightly convex curve and bears a row of faint humps at the endings of the concentric lines. However, not each one of these lines, but only approximately every second one, ends in such a hump.
The hinge is identical to that of L. spinifera, and also the umbo is smooth and tilted forwards and inwards as it is there. The colour is nearly clear white, the curvature of the shell is weak. The length of the shell is 11, the height 9.5 mm.
Comments. Currently accepted as Myrtea amorpha (Sturany, 1896) (MolluscaBase 2017) and recently recorded from cold seep communities in the deep eastern Mediterranean Sea (Olu-Le Roy et al. 2004). Its shape is totally unusual for lucinids and is indeed due to an accident during growth.
The shells stronger concentric stripes, the position of the umbo which is moved further to the front than in the type specimen, and the lesser arched ventral margin require a separation of this form as a variety of Axinus flexuosus Mont. and also suggest a certain relation to Axinus sarsii Phil., which was only found in the north to this date -the length of the shell is 7.5, the height 7 mm.

Comments. Currently accepted as Thyasira striata Sturany, 1896 (MolluscaBase 2017) and
recently recorded from cold seep communities in the deep eastern Mediterranean Sea (Olu-Le Roy et al. 2004).

Translation. From station 82 (2420 m)
There is a large number of right and left valves of this mysterious new bivalve, which are quite diverse in their sizes and of which scarcely any fit together.
The color on the outside of the shell is white, yellow, or brown and whitish on the inside with a yellow margin or monochrome yellowish to gray with no margin. Anterior and posterior sides are in most cases equally rounded. In some rarer cases, there is a faint suggestion of a beakformed ending, showing a slight dent at the transition of the ventral margin to the posterior margin. The outer surface of the shell is densely concentrically lined; the inside, smooth and shiny, shows two elongated vertical muscle scars and a very superficial/shallow pallial sinus at the posterior. The umbo is located at the anterior half of the shell and its tip tilted to the front and inside. At its front, a lunular-like indentation can be noticed.
The hinge is quite complex. In the right valve (Fig. 26), directly beneath the umbo there is an horizontal elongated tooth, compressed from top to bottom. In front of the umbo, namely beneath the anterior lower margin and separated by it through a groove, there is a second, also horizontal and flattened tooth. The two teeth are connected at their base, but leave a cavity above, respectively at the inwards turned part, between them. Behind the umbo, a bar advances parallel to the upper margin.
In the left valve (Fig. 27), a large set of teeth beneath the umbo strikes the viewer. Perpendicularly to the longitudinal plane of the shell, two curves become visible, leaning together at their convex sides, which makes the teeth seem double-toothed. When the shell closes, this set of teeth is embedded in a caving which is stretched between the two large teeth of the right valve and it seems as the aforementioned curves dock each of them. Between the "double tooth" and the upper margin which is broadened beneath the umbo, there is a groove and above, directly at the upper margin, a small flattened tooth, analogous to the right valve. Only in one specimen we find two horizontal and parallel arranged teeth instead. Also in the left valve there is a bar advancing behind the umbo parallel to the posterior upper margin which is prominent and tooth-like in some parts.
The hinge of this sort is similar to that of Cypricardia lithophagella Lam. (Kobelt Prodr. p. 390), and considering this, I find appropriate to introduce the new genus Isorropodon which is characterized by the described hinge and stands in the system directly behind Cypricardia.
Comments. The genus Isorropodon Sturany, 1896 was also introduced and is currently considered a valid genus within the vesicomyid subfamily Pliocardiinae (Krylova and Sahling 2010). I. perplexum is considered a valid specis (MolluscaBase 2017) and has been recently recorded from cold seep communities in the deep eastern Mediterranean Sea (Olu-Le Roy et al. 2004). Types noted and species described in detail by von Cosel and Salas (2001).

Family Lyonsiidae P. Fischer, 1887
Lyonsia aegeensis Sturany, 1896  fig. 3-3b) and might turn out to be, if it would be possible to comparably study a range of Lyonsia, merely a variety of L. formosa. For now, however, I have to isolate the present form, as it differs from the formosa specimen depicted in the Challenger work in the following points: 1. The size of the shell is much larger; the general form is more elongated. 2. The umbo is situated nearly in the middle, while it is moved further to the anterior in the Challenger specimen (see view from above). 3. The radial ridge which proceeds from the umbo towards about the middle of the lower margin is faintly indicated and only recognizable through a row of blister-formed swellings of the epidermis. The second ridge, which proceeds from the umbo towards the posterior lower margin of the shell, is clearly marked and describes a curve which is convex to the front, while this ridge is orientated towards the posterior upper margin with a weak convexity in its upper part. 4. There are 11 radially expanding ribs with densely packed spines behind the second keel (as compared to 7 in the Challenger specimen!). In addition to the 6 or 7 more prominent varices which are typical for L. formosa, there are several wavy elevations in the anterior half of the shell, which are less developed and positioned closer together. Here, these elevations occupy the space towards the umbo which seems to be open in the case of the Challenger specimen. 5. Finally, it can be mentioned that the upper margin forms a distinct angle with the posterior margin, by ending horizontally from the umbo and suddenly bending downwards, not slowly and gradually bending towards the posterior, as it happens in the Challenger specimen.
The ligament with the hemispheric ossiculum is beautifully visible in the here described specimen. Each shell has a horizontally emerging and upright carved plate beneath the umbo to accommodate the ligament including the ossiculum.
The shell from station 237 is merely 11 ½ mm long and 8 ½ mm high.

Family Verticordiidae Stoliczka, 1870
Pecchiolia berenicensis Sturany, 1896  This bivalve is white in colour, with a rough surface, unequilateral, and rhomboid in outline. The umbos are located at the anterior half of the shell. The downwards tilted dorsal margin is depressed (delimiting the lunula) and merges through a right angle directly with the lower margin which has an obtuse angle (with the tip in the middle). Posteriorly, the margin runs again through a right angle towards the posterior, convex bended upper margin. Therefore, there cannot even be any question of an anterior or posterior margin.
The right valve surpasses the left one in length and height. In fact, while that [right] valve measures 7.5 mm in length and 7.1 mm in height, this [left] one is only 7.1 mm long and 6.4 mm wide. The margin of the right valve, furthermore also more strongly arched, slightly surpasses the margin of the left valve when the shells are closed. The thickness of the entire bivalve is 5.5 mm.
There are 23 radial ribs running along the outside of the two valves, which show through the mother-of-pearl shining inside. Between them, there are a large number of delicate, waved concentrically arranged lateral lines.
The hinge is rather ordinary. In the right valve there is a strong, conic cardinal tooth beneath the front-and inwards orientated umbo; proceeding backwards (beneath the posterior upper margin) there is a rather long, in the mid part moderately projected, bar, which lies before a lateral tooth; embedded between the two, the cardinal and lateral tooth, is the horn-like ligament. Situated within the left valve is a deepening beneath the umbo to accommodate the cardinal tooth of the right valve. The posterior lateral tooth is present here again in the form of a bar, which is moved so far against the umbo that the horny inner ligament is placed right beneath it. Whenever the mussel is closed, the lateral tooth of the left valve is placed right in front of that of the right one and beneath the first one lies the ligament, as mentioned before.
The lunula, which is broad and heart-shaped and is positioned very deep, has not the same size in the two valves. The anterior upper margin of the right valve is convex at the relevant position and fits into an equivalent concavity of the opposite margin; the space of the lunula of the right valve is also larger than the part of the left valve.
The species at hand seem not to coincide with any of recognized species of the genera Verticordia or Pecchiolia to date, however it is closely related to Pecchiolia insculpta Jeffr.