Illustrated catalogue of type specimens of Volutidae (Gastropoda) in the Malacological Collection of the Museo de La Plata, Argentina

The Malacology Collection of the Museo de La Plata contains more 13,000 lots from various regions of Argentina and other South American countries. The Collection also includes 511 type lots. Among the oldest type specimens are a large series of marine gastropod from Patagonia which were studied by Fernando Lahille in 1895. He was one of the first’s naturalists of the Museo de La Plata, and there between 1893 and 1899, he made several studies in zoology. During that time, he described three species and forty varieties of Volutidae. Herein, we compare Lahille’s type specimens, label data, number, and specimen information to the original descriptions and illustrations of these taxa. Each taxon has been photographed in multiple views. This historic type material is entirely composed of shells. This work is the first of a series of photographic catalogues of type material from the Malacology Collection of the Invertebrate Division of Museo de La Plata.


Introduction
The Malacology Collection of the Museo de La Plata contains specimens from five mollusc groups, including from terrestrial, marine, and freshwater ecosystems. Of the over 13,000 lots that form the collection, almost 70% of these have been identified to species level. The collection includes 511 type lots. The specimens come from various regions of Argentina, and from other countries such as Brazil, Chile, Paraguay, Peru, Uruguay; a few are from other parts of the world. The lots are preserved in the traditional way, i.e. dry, wet, SEM stubs, and microscope slides, as well as frozen tissue for molecular studies.
The collection is continuously growing through projects from the museum's researchers, as well as by donations and legacies from outside researchers and collectors. It has also been expanded by various expeditions over the years, such as Hassler in 1870-1871, Hauthal in 1898, Bentart in 1898, Beaufils in 1898, Lahille in 1898, Moreno in 1899

Material and methods
During this project, the type materials of the Lahille Collection were separated, label data, number of specimens, and specimen information were compared to the original description (Lahille 1895). Specimens photographed in Lahille (1895) have the corresponding plate and figure numbers on them. We included collection catalogue numbers of the Malacological Collection of the Museo de La Plata (MLP-Ma), type status, and specimen number. We also compared all the specimens with the original figures, and we present some remarks.
For each taxon, we selected and photographed a morphologically representative specimen in apertural, lateral, dorsal, apical, and umbilical view. The rest of the specimens, which were earlier figured by Lahille, were only photographed in apertural view. Photographs were taken with a Nikon d80 camera, a Nikon DX af-s nikkor 18-135mm 1:3.5-5.6G ED lens, and using a Tiffen colour control chart.
The resulting catalogue is presented in alphabetical order according to species name in its original combination, followed by authority and year of publication, current name, and a summary of the description provided by Lahille. For each species, the varieties are detailed starting with typica and followed by the rest in alphabetical order. Name, combination, authority, and varieties are kept as mentioned by Lahille (1985).
The shell has accentuated coloured lines. It has a carina and tubercles on every whorl, slightly attenuated on the last whorl of the spire. The suture of the last whorl of the spire is almost at the same level as the row of tubercles of the penultimate one. The aperture is regularly arched and with three columellar folds.
Voluta ambigua subnodosa Lahille, 1895 Holotype: MLP-Ma 10857, ca 120 mm long × 65 mm wide, figured by Lahille (1895: pl. XI, fig. 9). Label reads: "1.subnodosa" (Fig. 5). Lahille (1895) mentioned that V. subnodosa Leach, 1814, is similar to this variety of V. ambigua. The shell has the last whorl expanded and smooth, and there are almost always Table 1. Voluta ambigua typica, specimens figured by Lahille (1895) with the detail of the inscriptions on their shells and figures here.  three very dark, narrow, angular transverse lines. The spire is short and consists of six whorls, of which the third and fourth whorl are subcarinate at the middle with small tubercles. The aperture is wide, pale orange-brown, and there are three columellar folds. The inferior fold is smaller than the others.
The diameter of the last whorl is higher than the double the diameter of the penultimate whorl.
The last whorl of the spire has a dilation that is much more accentuated upwards, and forms a false carina. The shells are thin and generally with three columellar folds.
This variety differs from the variety typica by having heavier shells and in being larger, with specimens over 190 mm long. The specimens that Lahille (1895) figured in plate VIII, figures 170 and 173 have not been found.
This species has a shell with longitudinal orange-brown lines, and without nodes. Lahille (1895) described seven varieties.      Lahille described this variety with fusiform or subturbinated shells, with a smooth surface (almost completely covered by the mantle). The colour is pale yellow with dark longitudinal zigzag lines. The last whorl is strongly carinate, almost perpendicular to shell axis. The aperture is broadly ear-shaped, with a triangular slit on the upper side, and three equal columellar folds. The total length of the shell is shorter than twice the width.     According to Lahille's description, the shells are thickwalled, dark, and can be up to 100 mm long by 45 mm wide. The upper part of the last whorl is regularly concave.
The specimens are elongated, with shells thinner than those of the typica variety. The aperture is narrow, almost regular oval. The carina of the last whorl is not evident and forms a roundish angle. The last whorl of the spire is convex. Carcelles (1944) treated this taxon as valid in his study of marine molluscs of the southern coast of Buenos Aires.   Table 4. Scale bars: 3 cm.   (1895). See references on Table 5. Scale bar: 5 cm.  According to Lahille (1895), the shells are longer than twice their width, and the last whorls are carinate. The upper columellar folds are not evident.

Voluta angulata luteola Lahille, 1895
Syntypes: MLP-Ma 10868, 5 specimens figured by Lahille (1895) (Table 7), 4 other specimens not fig-    The total shell length of this variety is almost as long as twice its width. The first few whorls are convex, and the aperture white.
The proportions of the shell of this variety are similar to luteola, but the carina is strongly oblique to the columellar axis.
According to Lahille (1895), this variety can reach up to 170 mm in length and 130 mm in width. The first three whorls of the spire are smooth; the last whorl covers entirely the tubercles of penultimate whorl. The suture is almost never undulated. The aperture is roughly This variety is similar to luteola, but the last whorl is more expanded and not carinate. The free edge of the aperture forms a curve.
There are five shells that have not been assigned to any variety of this species (MLP-Ma 10872). Two of them were not figured by Lahille (1895). Inscriptions on the remaining three specimens read: 1. "10.typica jov." pl. II, fig. 73  There are three groups of shells corresponding to V. angulata (MLP-Ma 14245). On these shells, are the following inscriptions: "calcarea", "subventricosa", and "nebulosa". These specimens were never described nor figured by Lahille (1895). semilunar and white to yellowish-orange. Generally, the shells have two unequal columellar folds. Sometimes the inferior fold fuses with the columella, so it is not visible, while in others, there are two wrinkles on each side of the upper fold. This variety differs from V. tuberculata in the absence of zigzag lines on the shell.
Lahille described the shells of this variety as more elongated and less conical than those of var. carinata. The penultimate whorl is always visible. The nodes of the last two whorls arise usually alternate, giving the name of this variety.
However, this variety was unfigured by Lahille (1895). The only specimen with this name on its shell also has the inscription "L V, F 31", which indicates its use in plate V, figure 31, which is typica according to the plate's legend. Lahille, 1895 Holotype: MLP-Ma 10881, 110.5 mm long x 78 mm wide, figured by Lahille (1895: pl. V, fig. 36). Label reads: "511", "1.carinata" (Fig. 30). Lahille (1895) described this variety as having a conic shell and with the penultimate whorl of the spire almost always separated from the last whorl of the spire. The external edge of the aperture forms an almost straight angle on the upper side, and the tubercles are on the carina.   fig. 39). Label reads: "510", "1.depressa" (Fig. 31).

Voluta colocynthis carinata
According to Lahille (1895), the first few whorls of the spire are small, and form a regularly convex surface. The lower part of the columella has a large inferior fold.

Voluta colocynthis globosa Lahille, 1895
Syntypes: MLP-Ma 10880, 2 specimens figured by Lahille (1895) (Table 11). Specimens over 170 mm long, width approximately 65% of total length (Fig. 32). Lahille (1895) described this variety as similar to V. colocynthis intermedia, but the shells are much more globose and always with tubercles on the last whorl of the spire. The first part of the last whorl rarely has nodes. The specimens are large, up to 200 mm long and 132 mm wide.
According to Lahille (1895), the shells of this variety are ovoid, up to 160 mm long and 110 mm wide, always without tubercles on the final half the last whorl or with tubercles rudimentary only. The free edge of the aperture is usually rounded. The penultimate whorl of the spire is completely hidden by the last one, the suture is rarely undulated, and there are two columellar folds which are mostly unequal.
The shells have the spire tall. The nodes on the last whorl of the spire are accentuated and rise above the suture. In large specimens, the upper angle of the aperture is 20-25 mm from the nodes.      (1895), with the detail of the inscriptions on their shells and figures here.

Figure of Lahille (1895) Detail Figure
Pl. X, fig. 3 "2. zonaria" 35a-e Pl. X, fig. 1 "1. zonaria" 35f The spire has five whorls, the first two smooth and the last three with strong nodes. The suture is undulate. The last whorl is without a carina but with tubercles from which arise rudimentary longitudinal ribs. The specimens are up to 70 mm long and 45 mm wide and heavier than V. colocynthis typica.     fig. 30). Label reads: Plate V, Fig. 30 "19.typica" (Fig. 37). Lahille (1895) mentioned only that this variety is intermediate between the typica and the carinata varieties.
Specimens matching Voluta colocynthis pseudomagellanica Lahille, 1895 have not been found in the MLP Collection. There are two shells (MLP-Ma 14246) with inscriptions referring to plate II, figure 50 and plate II, figure 69a but not assigned to any variety of this species.

Voluta fusiformis Kiener, 1839
Current name: Adelomelon beckii (Broderip, 1836). Lahille (1895) mentioned that the shells are up to 350 mm long and 170 mm wide, yellow or sometimes very pale, with yellowish-orange longitudinal zigzag lines that align to each node. There are narrow, slightly undulating spiral striae, which are sometimes cut by narrow growth lines. The spire of adults has eight whorls; the first three whorls are generally smooth and form a button. The lower sides of the nodes are prolonged into ribs, which are attenuate or disappear in adults. In large individuals, the nodes of the last whorl form a transverse fold.
According to Lahille (1895), the shell of this variety has no tubercles on the last whorl, or rarely, a small carina marks a tubercle line.
This variety has few, well-spaced nodes on the last whorl of the spire.
Lahille (1895) remarked on the similarity with V. ambigua and V. ancilla. Voluta ambigua has three coloured longitudinal lines that wide in some points; this character is not present in V. ancilla. Lahille (1895) described three varieties.

Voluta magellanica typica Lahille, 1895
Syntypes: MLP-Ma 10888, 3 specimens figured by Lahille (1895) (Table 16), the largest ca 135 mm long × 61 mm wide; 14 other specimens unfigured by Lahille (1895) (Fig. 41). Lahille (1895) described the shell of this variety as reaching 180 mm long by 90 mm wide, with six convex whorls on the spire. The shells vary from white to pale brown, with prominent dark lines. The aperture is almost oval and orange, pink, or light purple, with thin edges, and the lower columellar fold is not well developed. The juvenile forms have a reticulated surface, without tubercles; they have general aspect of V. ancilla but a little wider. The syntypes were divided into two series by Lahille.
According to Lahille (1895), this variety has a very depressed shell, with the last whorl globose, and with the aperture triangular, wider at the base. Three are strong, horizontal colour bands on the last whorl.
According with Lahille (1895), this variety is similar to V. magellanica curta, but the aperture is semicircular and the columellar edge is deeply indented at the folds. The specimens of this variety can reach up to 150 mm long and 90 mm wide.
According to Lahille (1895), this variety has the spire uniformly convex and the last whorl of the spire is very convex. The free edge of the aperture forms a regular curve.

Voluta paradoxa Lahille, 1895
Current name: Odontocymbiola magellanica (Gmelin, 1791). Lahille (1895) described this species without varieties. old specimens, the free edge of the aperture is up to 7 mm thick. The largest specimens reach 125 mm long and 85 mm wide and weighing up to 270 g. The spire has five or six whorls. The columella is thick, white or yellowish, and with four to five folds, of which the inferior is more developed.

Voluta oviformis fratercula Lahille, 1895
Syntypes: MLP-Ma 10891, 2 specimens figured by Lahille (1895) (Table 18; Fig. 46). According to Lahille (1895), this variety lacks tubercles but has a carina on the final part of the last whorl, which results in an angle on the free edge of the aperture, and a less pronounced carine next to the suture.
Lahille (1895) differentiated V. paradoxa from V. colocynthis pseudomagellanica and V. magellanica typica by differences in the juvenile shells. According to him, the shells are thick, similar to V. colocynthis pseudomagellanica. The specimens have discontinuous colour lines that can form three bands on the last whorl, similar to V. magellanica. The shells lack tubercles. The last whorl is ovoid and globose. Generally, there are three columellar folds, with the inferior fold smaller, and supernumerary folds are sometimes present. The shells are up to 180 mm long and 86 mm wide and can weigh up to 260 g.

Voluta tuberculata Wood, 1828
Current name: Odontocymbiola magellanica (Gmelin, 1791). Lahille (1895) described five varieties of this species, and mentioned the similarity of this species to V. colocynthis. This species is smaller than V. colocynthis and always has small lines or flames, usually in three rows.
According to Lahille (1895), adult shells reach up to 120 mm long and 67 mm wide, and are subturbinated. The suture between the penultimate whorl and last whorl is below the carina on the last whorl of the spire. The first two or three whorls of the spire are smooth, and the following three whorls are carinate and have tubercles. Usually, three equal columellar folds are present.
According to Lahille (1895), this variety has a short shell (140 mm long × 90 mm wide), with the last whorl globose, and with an eroded carina. The free edge of the aperture is regularly curved. The inferior columellar fold is small and sometimes with two supplementary upper folds.

Voluta tuberculata fulgurea Lahille, 1895
Syntypes: MLP-Ma 10893, 3 specimens figured by Lahille (1895) (Table 23); 77-121 mm long (Fig. 53).    *The legend of plate VIII, figure 162 indicates Voluta magellanica decipiens, a variety which is never mentioned in the text. No material exists with that name, so it is probably an error.   Figure 67a only indicates V. tuberculata, so it probably corresponds to this shell. On the MLP label, it is assigned to this variety with doubt. Lahille (1895) described the shells as elongate, with the last whorl large and ovoid, and with few tubercles. The penultimate whorl is convex and without tubercles.
Twenty one other specimens from Lahille's Collection (MLP-Ma 14250) have not been identified as representatives of any of the previously mentioned varieties.
Along with the material of Voluta ancilla, there are 16 other specimens (MLP-Ma 14244) with a label that reads "crocea". There is no variety with that name in the publication by Lahille (1895).