98 Mr. S. Stutchbury on two new genera of MoUusca. 



In general contour, this shell has so great a similitude to Chama, that 

 without opening it there would be no hesitation in pronouncing it of that 

 genus, belonging to Lamarck's division, " Crochets tournant de droit a 

 " gauche." Its internal differences are given in the generic description. 

 The species I characterise as follows : — 



CleidothjErus Chamoides. 



Tab. Supp. xlii. f. 5, 6, 7, 8. 

 C. testd invohtd, rufd, interne subviridi sub-margaritaced : vakd 

 dextrd majore profunda, latere antico adharente; latere convexo 

 claviculcB sulcata. 



Shell involute, brownish red, internally of a greenish pearly lustre, 

 attached by the anterior side of the right valve, which is of great depth ; 

 left valve but slightly convex ; the clavicular appendage with a groove on 

 the convex side. 



My specimens being destitute of colour, the figure has been taken by 

 G. B. Sowerby,jun., from one in his father's collection, which he found 

 among the stores of the late Mr. Huniphreys,but which, not having the clavi- 

 cular appendage, had been l;;id aside, until more perfect specimens should 

 decide its true characters. Mine were found attached to sand-stone rocks 

 by T. Young, Esq., R. N., together with an Aspergillum (perhaps agglu- 

 tinans of Lamarck) , some Chamse, &c. while searching near the entrance 

 of Port Jackson, pointed out to him as the s})ot where I discovered, in 

 1 286, the first living Clavagellae. 



The five following shells bear so close an analogy to Myochama, that 

 believing the four last to be inedited, I am induced to give specific de- 

 scriptions of them, adding them to the genus Anatina. I must, however, 

 premise, that the spoon-shaped teeth mentioned by Lamarck are absent 

 in each, but they possess the moveable appendage to the hinge, found in 

 most, if not all the shells placed in that genus by him. 



entirely inapplicable that I hesitate not to retain the appellation of Cleido- 

 thmrus, by which I had designated it. There is nothing in the shell to con- 

 nect it with Ostrea. 



