322 PSETJBAMUSSnJM. 



Genus PSEUD AMTJSSIUM (Klein), H. and A. Adams. 

 [Gen. Eec. Moll. vol. ii. 1858, p. 653.] 



Distinguished from its near ally Amussium by not having 

 radiating ribs on the interior of the shell ; whilst the auriculae 

 are unequal in size. 



Bruguiere ^ is generally credited with having been the first to 

 adopt Klein's Pseudamussium {em.), but on reference to his work 

 it will be seen that he is merely dealing with Klein's method 

 of classification of the Mollusca, and that although he gives a brief 

 description he does not quote any species in connection therewith 

 so as to typify the genus. At a later date, in the same work, 

 Deshayes^ mentions Pseiidatnussium, but although he gives a 

 diagnosis and illustrates it by quoting some species, he remarks 

 that "this genus has not been adopted." 



Messrs. H. and A. Adams appear to be the first to have actually 

 adopted it, though they quote a number of species some of which 

 are not typical of Pseudamussium as intended, apparently, by Klein. 

 The type of the genus, as selected by Stoliczka^ and as given below, 

 occurs in H. and A. Adams' list as a synonym, which, however, 

 is easily recognized. 



Type. — Peden exoticus, Chemnitz. 



Pseudamussium yahlensis, Tenison- Woods (sp.). 



1865. Pecten yahlensis, Tenison- Woods, Trans. Phil. See. Adelaide, pi. i. 



fig. 4. 

 1876. Pecten yahlensis var. semilavis, M'Coy, Prod. Pal. Vict. dec. iv. 



p. 13, pi. xxxiv. 

 1886. Pecten yahlensis, Tate, Trans. Roy. See. Soutli Aust. vol. viii. p. 110. 

 1893. Pecten yahlensis, Tate and Deunant, id. vol. xvii. pt. 1, p. 224. 

 1896. Pecten yahlensis, Pritchard, Proc. Eoy. See. Vict. vol. viii. n.s. p. 127. 



Shell suborbicular, thin; valves unequal, with dissimilar ornament. 

 Eight valve more convex than the left, surface having numerous 



1 Ency. Meth. Vers. i. 1792, p. 536. 



2 Ency. Meth. Vers. iii. 1832, p. 854. 



3 Mem. Geol. Surv. India, Cret. Fauna S. India, vol. iii. Pelecj-poda, 1871, 

 p. 426. 



