DON AX. 



Plate IV. 



Species 18. (Mus. Cuming.) 



DoNAX NAVICULA. Boti. tesM ollongo-rliomboided, yihho- 

 siuscula, solidd, Itsv'ujatd, obsolete radlatlm mlcatd, 

 epidermide pallkli corned nitente indutd, miilioidl/iis 

 mice/itralibus, latere antico acuminato-rotimdato, pos- 

 tico acmninato-tnincato, rostrato ; liinuld aredque jms- 

 ticd concavis, f/mieo-mffricantiius, nitentihiis. 



The boat Donax. Shell oblong-rhomboid, rather gib- 

 bous, solid, smooth, obsoletely radiately grooved, 

 covered with a pale shining horny epidermis ; umboes 

 nearly central, interior side acuminately rounded, 

 posterior acuminately truncated, beaked ; lunule and 

 posterior area concave, smoky-black, shining. 



Hanley, MS. (Mus. Cuming.) 



Hah. Gulf of Nicoiyo, Central America ; Cuming. 



A very distinct and characteristic species, both in form 

 and colouring. 



Species 19. (Mus. Cuming.) 



Donax anatinus. Bon. testa ovato-oblongd, versus mar- 

 ginem suhconipressd, radiatim tenuistriatd, albidd, epi- 

 dermide fidvesceiite indutd, ad mnbones subviolacels ; 

 latere antico rotmidato, postico obtuse decUvi-angulato, 

 vix truncato. 



The duck's bill Donax. Shell ovately oblong, rather 

 compressed towards the margin, radiately finely stri- 

 ated, whitish, covered with a fulvous horny epider- 

 mis, a little violet at the umboes ; anterior side 

 rounded, posterior obtusely slantingly angled, scarcely 

 truncated. 



Lamaeck, Anim. sans vert. (Deshayes' edit.) vol. vi. p. 

 249. 



Donax tnmculm, Auct. Brit. 

 Bonax ruber, Turton. 

 Cuneus vittatus, Da Costa. 



Hab. British Seas. 



The well-known species of onr coast, abundant on all 



antico subproducto, rotundato, postico nbnipte late 

 truncato. 



The lunuled Donax. Shell somewhat cylindrically ob- 

 long, rather thick, very gibbous, radiately densely very 

 finely grooved, fawn-coloured, concentrically darker- 

 banded ; anterior side somewhat produced, rounded, 

 posterior abruptly broadly truncated. 



Philippi, MS. (Mus. Cuming.) 



Hab. ? 



It is the posterior area, and not the lunule, as the name 

 given to this species would infer, is so prominently de- 

 veloped. 



Species 20. (Mus. Cuming.) 



Donax luntjlaris. Bon. testd stibcylindraceo-oblongd, 

 crassiiisctdd, valde gibbosd, radiatim dense tenuissime 

 sulcata, spadiced, concentrice saturate fasciatd ; latere 



September, 1854. 



Species 21. (Mus. Cuming.) 



Donax cdltee. Bon. testa snhjhxiwso-oblonijd, medio 

 contractd, radiatim dense tcniiisulcatd, ccernlescente- 

 grised, violaceo pallide tiiicfd, intus intense violaced; 

 latere antico rotmtdato, postico gibboso, declivi-rostruto, 

 vix angulato. 



The plough-share Donax. Shell somewhat flexuously 

 oblong, contracted in the middle, radiately densely 

 finely grooved, bluish-grey, tinged with pale violet, 

 deep violet within ; anterior side rounded, posterior 

 gibbous, slantingly beaked, scarcely angled. 



Hanley, MS. (Mus. Cuming.) 



Hab. Gulf of California. 



Distinguished from all other species by its peculiar 

 7tfo(Zio/a-like form. 



Species 22. (Fig. a, b, Mus. Cuming.) 



Donax Cayennensis. Bon. testd ovato-cnneatd, mbtri- 

 gond, compressd, dense tenuissime sulcata, liris posticis 

 creberrime crispato-clatJiratis ; latere antico rotundato, 

 postico abrupte convexo-truncato ; lutescente-albd, ad 

 mnbones rosed, versus marginem griseo-fasciatd, vel 

 violaceo-fuscd, ad mnbones radiatd. 



The Cayenne Donax. Shell ovately wedge-shaped, sub- 

 triangular, compressed, densely very finely gTooved, 

 posterior ridges very closely crisply latticed ; anterior 

 side rounded, posterior abniptly convexly truncated, 

 yellowish-white, rose at the umboes, grey banded 

 towards the margin, or violet-brown, rayed at the 

 umboes. 



