533 



THE SYSTEMATIC POSITION OF PURPURA TRITONI- 

 FORMIS OF BLAINVILLE. 



By H. Leighton Kesteven. 



(Plate xxix.) 



A good deal of doubt has existed as to the systematic position 

 of the mollusc under discussion. It was first described as a 

 Purpura by Blainville.* Kienerf placed it in the same genus in 

 his second section Semi-ricinules. Dunkerj described it as 

 Adamsia tyinca, classing it with Cominella. Tenison-Woods§ 

 subsequently showed that Adamsia was preoccupied by Prof. E. 

 Forbes, and replaced it by Agnewia. Tr5^on,l| who next dealt with 

 it, transferred the species to Urosalpynx on the strength of its 

 purpuroid operculum. His synonymy of it embraced Adamsia 

 typica, Dkr., A. adelaidoi, Ad. & Ang., and Purpura neglectOy 

 Angas, the last two as possible varieties. No one acquainted 

 with P. neglecta in Sydney Harbour would agree that it conforms 

 either generically or specifically with P. tritoniformis. The 

 validity of A. adelaidce is maintained by Dr. Verco.H 



Watson, "^"^ practically ignoring Woods's correction, re-instated 

 Adamsia as a subgenus of Cominella. The operculum, which 

 Angasft had previously stated to be purpuroid, he considered 

 evidence for, rather than against, this classification. The species 

 is omitted from the Conchologica Iconica, the Conchlyien Cabinet, 

 and the Thesaurus Conchyliorum. 



*Nouv. Ann. du Mus. d'Hist. Nat. Tome i. p. 221, pi. 10, fig. 10, 1833. 



+ Coq. Viv. Purpurifere, i., pi. 8, fig. IS. 



X Proc. Zool. Soc. 1856. 



§ Proc. Koy. Soc. Tasmania for 1877. 



II Man. Conch. Vol. ii., 1880, p. 156. 



IT Trans. Roy. Soc. S. Aust., 1895. Vol. xix., p. 101. 



** Chall. Kep. Zool. Vol. xv.. Gasteropoda, 1885, p. 214. 



ft Proc. Zool. Soc. 1867, p. 192. 



