181 



Notes on South Australian Marine Mollusca, 

 with Descriptions of New Species. -Part XV. 



By Jos. C. Verco, M.D. (Lond.), F.R.C.S. (Eng.). 



[Read October 10, 1912.] 



Plates XV. and XVI. 



This paper is a continuation of the series from page 215 

 of vol. xxxv. of 1911, and embraces all the known South Aus- 

 tralian species of Helcioniscus, Patella, Nacella, Acmcea, 

 Phenacolepas, Haliotis, Scissurella, and Schismope. It dis- 

 cusses also several species which have been attributed to South 

 Australia, but are not recognized as occurring here. 



Helcioniscus tramosericus, Martyn. 



Patella tramoserica, Martyn, Univ. Conch., t. 16, P. (Hel- 

 cioniscus) tramoserica, Martyn, Verco, Trans. Roy. Soc, S.A., 

 1906, vol. xxx., p. 205. 



Helcioniscus diemenensis, Philippi, Gatliff and Gabriel, Proc. 

 Roy. Soc, Victoria, 1908, vol. xxi. (New Series), part 1, p. 282. 



Gatliff and Gabriel discarded the name P. tramoserica, 

 Martyn, because the type locality was North America, and no 

 Victorian specimen was exactly like his figure ; but in answer 

 to enquiries by Mr. Gabriel, Dall has since written that 

 Martyn's species does not occur on the coasts of America, and 

 that it is probably Australian or New Zealand. Very likely 

 Martyn obtained it from Australia, but by mistake gave it 

 an American habitat. 



It occurs all along the South Australian coast from the 

 east as far towards the west as Venus Bay. At St. Francis 

 Island it is very rare and small, up to 18 mm. • so it seems 

 to fade out along our west coast. It was not taken at any 

 place along the south or west coast of Western Australia, its 

 place being taken by Patella neglecta. 



Helcioniscus illibratus, Verco. 



Helcioniscus illibratus, Verco, Trans. Roy. Soc, S.A., 1906, 

 vol. xxx., p. 205, pi. x., figs. 6-14: Type locality — Spencer 

 Oulf ; Hedley, Commonwealth of Australia, Fisheries, part 1, 1911, 

 p. 93, "100 fathoms, 40 miles south of Cape Wiles, South Aus- 

 tralia." 



Dredged in 15 to 20 fathoms off St. Francis Island, 5 

 dead. Taken in Western Australia, as far round as Rottnest 

 Island. 



