Tetrachaelasma southwardi Newman & Ross, 1971. Intraspecific variation of opercular plates among the material collected at 1950 m depth. Specimen (MACN-In 44478f): A, D. Left tergum in external and internal views, respectively; B, C. Left scutum in external and internal views, respectively. Specimen (MACN-In 44478a): E, H. Right scutum in external and internal views, respectively; F, G. Right tergum in external and internal views, respectively. Specimen (MACN-In 44478b): I, L. Right scutum in external and internal views, respectively; J, K. Right tergum in external and internal views, respectively. Specimen (MACN-In 44478l): M, N. Left and right terga in external view; O, P. Left tergum and scutum in external view. Scale bars: 10 mm.

 
 
  Part of: Chiesa IL, Pereira E, Roccatagliata D (2024) On the occurrence of the deep-sea barnacle Tetrachaelasma southwardi Newman & Ross, 1971 (Cirripedia, Balanomorpha, Bathylasmatidae) in the Mar del Plata Submarine Canyon, Argentina: supplementary description and taxonomic remarks on the genus. Zoosystematics and Evolution 100(2): 603-623. https://doi.org/10.3897/zse.100.118912