Roseaplagis caelatus explained

Roseaplagis caelatus is a species of small sea snail in the family Trochidae, the top shells.

Description

It is smaller than Cantharidus sanguineus (height: 5.5 mm, diameter 4.5 mm) but it is more deeply ribbed and its grooves are wider.^[1] The imperforate shell is more deeply ribbed, and the ribs narrower. They number 5 to 7 on the penultimate whorl, 15 to 16 on the body whorl. Sometimes they are obsoletely granose through being crossed by growth lines. The columella shows a slight swelling in the middle.^[2]

Distribution

This marine species is endemic to New Zealand and occurs off the Foveaux Straits; Port Pegasus, Stewart Island; Snares and Bounty Islands

Subspecies

The former subspecies have been named:

• Micrelenchus caelatus archibenthicola Dell, 1956: synonym of Cantharidus caelatus mortenseni Powell, 1933; synonym of Roseaplagis mortenseni (Odhner, 1924)
• Micrelenchus caelatus bakeri Fleming, 1948: synonym of Roseaplagis artizona A. Adams, 1853 (Odhner, N.H.J., 1924)
• Micrelenchus caelatus elongatus (Suter, 1897): synonym of Cantharidus caelatus elongatus (Suter, 1897); synonym of Roseaplagis artizona A. Adams, 1853
• Micrelenchus caelatus morioria Powell, 1933: synonym of Cantharidus caelatus mortenseni Powell, 1933; synonym of Roseaplagis mortenseni (Odhner, 1924)
• Micrelenchus caelatus mortenseni (Odhner, 1924): synonym of Roseaplagis mortenseni (Odhner, 1924)

References

• F.W. Hutton, Revision of the recent rhipidoglossate and docoglossate Mollusca of New Zealand; Proceedings of the Linnean Society of New South Wales, ser. 1 v. 9 (1884)
• Powell A. W. B., New Zealand Mollusca, William Collins Publishers Ltd, Auckland, New Zealand 1979
• Marshall B.A. 1998. The New Zealand Recent species of Cantharidus Montfort, 1810 and Micrelenchus Finlay, 1926 (Mollusca: Gastropoda: Trochidae). Molluscan Research 19(1): 107-156

Notes and References

1. https://archive.org/details/manualofconcholo111tryo Tryon (1889), Manual of Conchology XI, Academy of Natural Sciences, Philadelphia
2. https://archive.org/details/manualofnewzeala00sute Suter H. (1913-1915), Manual of New Zealand Mollusca; Wellington, N. Z. :J. Mackay, govt. printer,1913-1915