Zoological Society. 303 



Long. 3j ; alt. 8 poll. Mus. Stainforth, Saul, Walton. 



Hab. ad oras Novae Hollandiae. 



The Crassatella castanea is the largest and perhaps the best defined 

 species of the genus ; its shell is covered with a shining horny epi- 

 dermis, and both valves are singularly eroded at the umbones. I 

 know of three specimens of this fine shell, and each of them fully 

 exhibit this last-mentioned peculiarity. 



2. Crassatella Kingicola. Lamarck, Anim. sans vert, vol. v. 

 p. 481 ; Reeve, Conch. Icon. Crassatella, pi. 1. f. 5. 



Hob. ad oras Novae Hollandiae. Mus. Stainforth. 

 A specimen of this species, in the possession of the Rev. Mr. 

 Stainforth, is the only one that I have seen. 



3. Crassatella decipiens. Crass, testd ovatd, subgibbd, cpider- 

 mide fused indutd, vivide radiatd, radiis ab umbonibus ad margines 

 sccpe extensis ; latere antico subangulato, striis brevibus ornato ; 

 postico subquadrato, parum productiore. Reeve, Conch. Icon. 



Crassatella, pi. 1. f. 4. 



Long. 2± ; alt. 2£ poll. 



Hab. ad oras Novae Hollandiae. 



Crassatella Kingicola, Nobis (falso), Conch. Syst., vol. i. pi. 44. f. 3. 



This species, which has lately arrived from New Holland in great 

 abundance, has been received by most collectors as the Crassatella 

 Kingicola of Lamarck ; I moreover regret that it has been errone- 

 ously figured under that title in my ' Conchologia Systematica.' This 

 error was kindly pointed out to me by Mr. Sowerby, and I am now 

 satisfied that the shell of Lamarck's Crassatella Kingicola, which is 

 accurately figured in the ■ Genera of Recent and Fossil Shells/ is 

 one of extreme rarity. Mr. Cuming possesses a gibbous variety of 

 the C. decipiens, but it is not sufficiently distinct to demand especial 

 notice. Mr. Owen is we believe engaged upon the anatomy of this 

 species. 



4. Crassatella pulchra. Crass, testd ovato-trigond, depressd, 

 obsolete radiatd, epidermide crassd, fibrosd, molliusculd, indutd; 

 transversim sulcata, sulcis profundis, regularibus ; latere antico 

 rotundato ; postico subangulato. Reeve, Conch. Icon. Crassatella, 

 pi. 3. f. 16. 



Long. 2J'; alt. 2 poll. Mus. Cuming, Stainforth. 



Hab. ad oras Novae Hollandiae. 



De Blainville appears to have figured this shell in his ' Manuel 

 de Malacologie* as the Crassatella sulcata of Lamarck ; but it is of a 

 totally different form, nor does it agree with the Mactra sulcata of 

 Bruguiere, to which he refers in the ' Encyclopedic Methodique' ; I 

 therefore now propose to distinguish it by the above new title. The 

 shell of the Crassatella sulcata approaches rather in form to that of 

 the Crassatella rostrata, the anterior side of which is specially cha- 

 racterized as being productiore ; the grooves too in that species run 

 irregularly across the valves, and are not parallel with the lines 

 that mark the increase of growth. The shell of the Crassatella pul- 

 chra, on the contrary, is of a plain triangular form ; the posterior 



