24 DESCRIPTION OF FIFTY-TWO SPECIES OF UNIONID^. 



Hab. — Australia, C. M. Wheatley. 



My cabinet and cabinet of C. M. Wheatley. 

 Diam. 1, Length 1-7, Breadth 2'8 inches. 



Shell closely and slightly sulcate, regularly elliptical, compressed, slightly ine- 

 quilateral; substance of the shell somewhat thick, somewhat thicker before; beaks 

 a little prominent; ligament very thin, long and nearly concealed; epidermis dark 

 brown, shining, Mdthout rays, with very distant marks of growth ; umbonial slope 

 very slightly raised and rounded ; posterior slope carinate, narrow elliptical ; car- 

 dinal teeth small, lamellar, oblique, double in the right and single in the left valve ; 

 lateral teeth long, lamellar, nearly straight and single in both valves ; anterior 

 cicatrices confluent, large and slightly impressed; posterior cicatrices confluent, 

 large and very slightly impressed ; dorsal cicatrices placed in a row across the cen- 

 tre of the cavity of the beaks ; cavity of the shell shallow and wide ; cavity of the 

 beaks very shallow and rounded; nacre white or salmon color and slightly iridescent. 



Remarks. -^1 owe to my friend Mr. Wheatley the possession of the specimen 

 figured. He has two similar ones in his extensive and valuable collection. This 

 species is remarkable for having the lateral teeth single in both valves. The cardi- 

 nal teeth are small, and double only in the right valve, the upper lobe of the tooth 

 of which is very small. The lines of growth are broad and very distant. The beaks 

 are too imperfect to exhibit their character. In outline it is near to Thwaitesii 

 (nobis), but it is higher in the carina than that shell and differs in the teeth as 

 well as in the character of sulcation of the disk, Thwaitesii being smooth. It 

 resembles also vittatus (nobis), but that species is more inflated, the beaks more 

 terminal, and the marks of growth very much closer. It cannot be confounded 

 with Lamarck's Australis, that species being smooth and obovate. (See Philippics 

 Concha/lien, Tab. 5, fig. 5.) 



I have great pleasure in dedicating this species to the distinguished and able 

 author of British Conchology, &c., J. Gwyn Jefi'reys, F.E.S., &c. &c. 



Anodonta exilior. pi. 7, fig. 21. 



Testa alata, Isevi, obovata, iaflata, valde insequilaterali ; valvulis exilissimis ; natibus prominulis, ad 

 apices minute undulatis; epidermide vel olivacea vel brunea, polita et eradiata; margarita coeru- 

 lea et valde iridescente. 



Shell winged, smooth, obovate, inflated, very inequivalve, valves exceedingly 

 thin ; beaks somewhat prominent, minutely undulate at the tips ; epidermis olive 

 or brown, polished and without rays ; nacre blue and very iridescent. 

 Proc. Acad. Nat. Sci., 1871, p. 188. 



