304 ' THETIS " SCIENTIFIC RESULTS. 



Angas, who had collected the species in both countries, writes 

 that the South Australian Pecten " is without doubt the /■*. lati- 

 costatus of Gray from New Zealand."* Tenison Woods remarks 

 that the Tasmanian and New Zealand forms can only be parted 

 by those who consider geographic isolation a specific character. •)* 

 Hutton agrees in uniting the New Zealand species to the Aus- 

 tralian. ± 



On the other hand, Tate, after mature consideration, ranked 

 the Australian species apart from that of New Zealand. § This 

 view had by inference the support of Sowerby, Reeve and Smith. 



The variations in colour and contour of the Austi'alasian Scallop 

 described by Tate are not, in my opinion, sufficient or persistent 

 enough for specific rank. The Australian and New Zealand 

 shells are, therefore, to be united under one name. 



Lamarck gave no localit}^ for his Pecten medius when he 

 described it. It has escaped the notice of all conchological 

 writers that Deshayes (who doubtless wrote in view of Lamarck's 

 type) has redescribed Pecten mediu>i, and added, " Elle vient des 

 mers de la Nouvelle Zelande, ou elle paroit aussi commune que le 

 Pecten maximus sur nos c6tes."|| 



Lamarck had ample collections of the common and conspicuous 

 shells from New Zealand, Tasmania and Southern Australia. 

 That our Scallop had apparently escaped his notice was an 

 anomaly which suggested the present inquiry. 



Because Lamarck referred interrogatively to the figure of a 

 shell from the Red Sea, he has been misunderstood as having 

 described Red Sea material. It is beyond the limits of this 

 article to discuss whether the species from the Red Sea and the 

 West Indies, generally known as P. inedius, is or is not that 

 species. However, that the New Zealand species, and hence the 

 Australian, is the real Pecten medius, Lamarck, is certain. 



In 11-15 fathoms off the Crookhaven River. 



A M U S I U M, Schumacher. 



AMUSIUM THETIDIS, sp. nov. 



(Fig. 49.) 



Station 49. 



Yalve small, thin, white, translucent, compressed, equilateral, 

 externally glossy and concentrically grooved by reverse imbricating 

 sculpture, the internal lyrte visible through the shell. The 

 anterior auricle well developed, without ctenolium. Hinge line 

 long, slightly concave, umbo projecting. Within are ten slender 



* Angas— Proc. Zool. Soc, 1865, p. 656. 



+ Ten. Woods -Proc. Roy. Soc. Tasm. for 1877 (1878), p. 56. 



t Hutton— Proc. Linn. Soc.N.S.W., ix., 1884 (1885), p. 532. 



§ Tate — Proc. Roy. Soc. Tasm. for 1886 (1887), p. 115. 



II Deshayes— Encycl. Meth., Vers., iii., 1832, p. 715. 



