43<> Transactions. 



Patelloida perplexa (Pilsbry, 1891). [P. 75.] 



This is the only species of " Acmaea " or limpet at present commonly 

 acknowledged as specifically identical in Australia and New Zealand. 

 Pilsbry's name was aiv< n to an Australian shell, and comes into use, as 

 Hutton, who first described it from New Zealand, unfortunately selected a 

 preoccupied name. 



A summary of my classification of the New Zealand " Acmaeidae " would 

 read, — 



Genus Radiacmea nov. 



Radiacmea cingulata (Hutton, 1883). 



rubiginosa (Hutton, 1873). 



Genus Atalacmea nov. 



Atalacmea unguis-almae Lesson. Synonyms : Patella fragilis Chem- 

 nitz, 1795 (non-binomial) ; Patelloida fragilis Quoy and Gaimard, 

 1834 ; Patella solandri Colenso, 1844. 

 Genus Notoacmea nov. 



Notoacmea campbelli (Filhol, 1880). 



— — daedala (Suter, 1907). 



subsp. subtilis (Suter, 1907). 



helmsi (E. A. Smith, 1894). 



var. leucoma (Suter, 1907). 



intermedia (Suter, 1907). 

 parviconoidea (Suter, 1907). 



subsp. nigrostella (Suter, 1907). 



- pileopsis (Quoy and Gaimard, 1834). Synonyms : Patella 

 sturnus Hombron and Jacquinot, 1841 ; Patelloides antarctica, 

 id. ib. ; Patella cantkarus Reeve, 1855. 



Notoacmea scapha (Suter, 1907). 



suteri nov. Svnonvm : Acmaea roseoradiata Suter, 1907, not 



Smith, 1901. 

 Genus Patelloida Quoy and Gaimard, 1834. Synonym : Collisellina 

 Dall, 1871. 

 Patelloida stella (Lesson). 

 s — siibsp. corticata (Hutton, 1880). 



- pseudocoiticuta (Iredale, 1908). 

 perplexa Pilsbry (1891). Synonym : Patella octoradiata Hutton, 



1873, not Gmelin, 1791. 



Genus Cellana (H. Adams, 1869). [P. 78.] 

 In the svnonvmy of Helcioniscus Dall, 1871, is placed " Cellana 

 H. Adams, P.Z.S.", 1869, 274 ; type, Nacella cernica, H. Ad." In the 

 Man. Conch., vol. xiii, 1891,. Pilsbry (pp. 149-50) noted: 'This species 

 is the type of H. Adams's subgenus Cellana. It probably belongs to 

 Helcioniscus rather than to Nacella or Patinella. The name Cellana has 

 priority over Helcioniscus, but it has not been adequately defined." 



Under the present laws governing nomenclatural usage the lack of 

 definition does not invalidate a generic name, and consequently Cellana 

 must displace Helcioniscus. Helcioniscus was only provisionally introduced 

 by Dall, who was unaware of H. Adams's Cellana. 



Pilsbry, in this volume of the Man. Coch., did not use names for Acmaeas 

 and limpets in accordance with the rules now in use, and many alterations 

 are now necessary. 



