CRASS ATELLA— Plate III. 



Species 16. (Mus. Cuming.) 

 Crassatella pulchra. Crass, testd ovato-trigond, de- 

 pressd, obsolete radiatd, epidermide crassd, fibrosa, 

 molliusculd, indutd ; transversim sulcatd, sulcis pro- 

 fundis, regularibus ; latere antico rotundato, postico 

 subangulato. 

 The beautiful Crassatella. Shell ovately triangu- 

 lar, depressed, very faintly rayed, and covered with 

 a thick, soft, fibrous, light brown epidermis ; trans- 

 versely grooved, grooves deep and regular ; anterior 

 side rounded, posterior nearly angular. 

 Reeve, Proceedings Zool. Soc, 1842, p. 43. 



Crassatella sulcata, De Blainville, Malac, pi. 73. f.4. 

 Hub. Coast of New Holland. 



De Blainville appears to have figured this shell in his 

 ' Manuel de Malacologie ' as the Crassatella sulcata of 

 Lamarck, and Deshayes refers to it as such in his new 

 edition of the ' Histoire des Animaux sans vertebres ;' 

 it is not, however, of the same form as the shell de- 

 scribed by Lamarck under that title, being neither gibbd 

 nor latere postico productiore, nor does it agree with 

 the figure in the * Encyclopedie Methodique,' to which 

 De Blainville refers. In the shell I have fixed upon as 

 Crassatella sulcata the grooves are narrow and not par- 

 allel with the lines of growth ; in this shell the grooves 

 are broad and deep, and exactly parallel with the same. 



Species 17. (Mus. Saul.) 



Crassatella ornata. Crass, testd trigond, subdepressd, 

 pallidd, lineis spadiceis brevibus, longitudinalibus, ra- 

 rie pictd, transversim striatd ; intus albdque brunned, 

 margine tenuiter crenulato ; latere antico rotundato, 

 postico flexuoso, angulato. 



The ornamentedCrassatella. Shell triangular, some- 

 what depressed, transversely striated, of a pale 

 brown colour, variously painted with sharp, reddish 

 angular lines ; interior white, very dark chocolate- 

 brown under the hinge and along the posterior side ; 

 margin faintly crenulated ; anterior side rounded, 

 posterior flexuous and angular. 



Reeve. Proceedings Zool. Soc, 1842, p. 46. 

 Mesodesma ornata ? Gray. 



Hob. ? 



This shell approaches so near in its characters and 

 general resemblance to a figure in Griffith's ' Cuvier's 

 Animal Kingdom,' pi. 22. f. 6, under the title of Meso- 

 desma ornata, that we venture to consider it the same, 

 though certainly not referable to that excellent genus. 



Species 18. (Mus. Saul.) 



Crassatella divaricata. Crass, testd orbiculari-ovat 

 fulvo-rubescente , maculis angularibus spadiceis, ph 

 minusve connexis, vivide variegatd ; bifariam slriat 

 striis antice transversalibus, postie'e obliquis ; inti 

 albicante prope marginem violaced ,• lateribus amb 

 bus rotundatis, margine crenulato. 



The contrarily striated Crassatella. Shell orl 

 cularly ovate, and of a yellowish brown coloi; 

 vividly variegated with rich dark angular spol 

 more or less connected with each other and pas 

 ing over each valve in irregular festoons ; striati 

 in two different directions, stria? on the anteri 

 half of the shell transverse, on the posterior hi 

 oblique ; interior white, violet colour near the ms 

 gin ; both sides of the shell rounded ; margin cr 

 nulated. 



D'Orbignt, Moll, des lies Canaries, p. 106. 

 Venus divaricata, Chemnitz. 

 Venus contraria, Gmelin. 

 Crassatella contraria, Lamarck. 



Hab. Coast of Guinea, Lamarck ; Lancerotte, Car.a 

 Islands, D'Orbigny. 



The Crassatella divaricata is a very characteristic sp 

 cies, and may be readily distinguished by the peculi 

 manner in which it is striated ; the strife over one hi 

 of the shell running transversely, and over the other o 

 liquely. 



Species 19. (Mus. Saul.) 



Crassatella Donacina. Crass, testd ovato-trigond, su 

 gibbd, epidermide tenui indutd, paululum radiatd, m 

 bonibus plicato-rugosis ; latere antico subangu(ai 

 p/icis brevibus ornato, postico subquadrato. 



The Donax-shaped Crassatella. Shell ovately ti 

 angular, rather gibbous, covered with a thin ej. 

 dermis and slightly radiated ; umbones strong 

 plaited ; anterior side rather angular and adorm 

 with short plaits, which are continued across tl 

 shell on approaching the umbones, posterior sii 

 somewhat square. 



Lamarck, Anim. sans vert. (Deshayes' edit.), vol. i 

 p. 110. 



Hab. Coast of New Holland. 



The shell which I have figured in illustration of tl 

 species appears to be the variety which Lamarck notin 

 as having the umbones strongly plaited. 



