261 



ON THE ANATOMY OF HELIX POLITISSIMA, PFETFFER, OF 

 CEYLON, AND ON ITS POSITION IN THE AKIOPHANTINiE. 



By Lieut. -Colonel H. H. Godwin-Atjstex, F.R.S., etc. 



Head 14th June, 1901. 



PLATE XXYI. 



Ariophanta (Ravana, n.subgen.) politissima (Pfeiffer). 



Helix politissima, Pfr. : Proc. Zool. Soc, 1853, p. 125; Mon. Helic, 



vol. iv, p. 45. Reeve : Conch. Icon., pi. clxxxvi, tig-. ] 292. 



Hanley & Theobald : Conch. Indica, p. 15, pi. xxxi, figs. 8, 9. 

 Nanina [Xestd) politissima, Pfr. : Vers., p. 120. Alhers : Die 



Heliceen, 1860, p. 51, the habitat there given is " Salomon's 



Inseln." l 

 Macrochlami/s (sec. A) politissima, Pfr. : Theobald, Cat. Land and 



Fresh-water Shells Brit. Ind., p. 18. 

 Nanina (Macrochlamys) politissima, Pfr. : Nevill, Hand List Moll. Ind. 



Mns., p. 22. 

 Nanina (Xestina) politissima, Pfr. : G. Pfeffer, Abh. Geb. Nat. Ver. 



Hamburg, Bd. vii, Abth. 2 (1883), p. 13. 



"With reference to this last citation, Pfeffer appears to have 

 restricted Xestina to the following species (having originally, when 

 creating the genus in 1878, included other species, of which one, 

 mentioned by name, is a Siamese shell, viz. N. Siamcnsis, l'fr.) : — 

 Xestina listrialis(Beck),X. Maderaspatana (Gray), X. Belangeri 'i '(Desh.), 

 X. Tranquebarica (Fab.), X. ligulata (Fer.), all from Southern India, 

 and finally, X. politissima, from Ceylon This last, however, cannot 

 be the mollusc I now describe, for Pfeffer gives the radula as having 

 tbe formula 22 : 1 1 : 1 : 11 : 22, which thus differs both in the number 

 of admedian and marginal teeth : no other part of its anatomy is 

 mentioned, and probably was not seen. An error has evidently 

 occurred in the identification, and I would suggest that some species 

 of the genus Eurychlamys must have been before the author, for the 

 above formula agrees with that of E. regulata, a smooth, glassy shell, 

 which might very possibly be mistaken for the true politissima. 



As to Xestina, which was never properly described in the first 

 instance, it would save so much doubt and confusion if authors, when 

 creating a new genus or subgenus, would distinctly name one species 

 as the tj T pe, and not give half a dozen or more, of which in most cases, 

 and particularly in the mollusca, the anatomy has yet to be made known. 



1 Possibly another species if the shell seeu by Albers came from that locality. 



