A S T A R T E. 



Plate I. 



Genus ASTARTE, /. Sowerhy. 



Testa eequivaUns, inmquilateralis, subovata, vel orbicu- 

 laris, vel subtrigona, ■plcrumqv£ subcompressa ; 

 concentrice riigata, epidermide crassa induta, dausa. 

 Impressiones muscidares duo;, magnce, snhreniformes. 

 Imprcssio pallii integra. Cardo iitnhjiie valcd 

 Iridcntatd. Ligamentum eodermtm, area diirsali 

 et lunula excavatis. 



Shell equivalve, inequilateral, subovate, or orbicular, or 

 subtrigonal, generally subcompressed ; concentri- 

 cally wrinkled, covered with a thick epidermis, 

 closed. Muscular impressions two, large, rather 

 kidney-shaped. Impression of the mantle entire. 

 Hinge tridentate in each valve. Ligament 

 external, with dorsal area and lunule excavated. 



Sijn. Crassina, Lamarck. Tridenta, Schum. 



The shells of this genus are not liable to be con- 

 founded with those of any other, the several characters 

 included in the description being pretty constant in all. 

 The minute Asfarte trigoimlaris is the only exception, 

 and is very abnormal in form. The concentric 

 wrinkles have in most species a tendency to become 

 less prominent towards the centre, and even to dis- 

 appear altogether towards the margin of the shell All 

 the species, excepting the Mediterranean A. Jiisca, 

 inhabit northern seas ; Norway, (ireenland. North 

 America, Ac, being the chief places in whose sandy 

 shores they burrow. 



Species 1. (Fig. a, b, Mus. Sowerby.) 

 AsTARTE CASTANEA. Asf. tcstd suborHcuIari, aJtd, 

 obsolete radiatim sulcatd ; rugis concentricis dis- 

 tantibns, vix prominentibus ; versils marginem sub- 

 evanidis, latere antico brevissimo; ■umbonibus promi- 

 nentibus ; margine dorsali utrinqtie valdi declivi. 

 The chestnut Astarte. Shell suborbicular, elevated, 

 obsoletely radiately grooved ; concentric wrinkles 

 distant, scarcely prominent, partly disappearing 

 towards the margin, anterior side very short ; 



umboes prominent ; dorsal margin much sloped 



on each side. 

 Say. American Journal of Science, 1830, Conch. PI. I. 

 Astarte crassidciis, Brod. and Sowb. ? 

 Hub. Arctic Seas. 



Species 2. (Fig. a, b, Mus. Brit.) 



Astarte compressa. Ast. testa parvd, suborbiculari, 

 compressd, plusmimtsve elevatd ; nigis concentriciis 

 jMirvis ; umbonibus prominentibus, marginihis dor- 

 salibus valde declivis ; latere antico brevinsimo ; 

 latere postico vix truiicato. 



The compressed Astarte. Shell small, suborbicular, 

 compressed, more or less elevated ; concentric 

 wrinkles small; umboes prominent, dorsal margins 

 much sloped ; anterior side very short ; posterior 

 side scarcely truncated. 



Montagu (Venus). Testacea Britaiinica, Sup., p. 43. 



Venus Montagui, Dillwyn. 



Astarte striata, Gray. 



Astarte multicostata, Macgillivray. 



Hab. Great Britain and Norway. 



The varieties differ in form and elevation, and some 



specimens are more compressed than others. 



Species 3. (Fig. a, b, Mus. Sowerby.) 



Astarte sulcata. Ast. testa subquadratd vel orbicu- 

 lari-svbtriyond/ sulcis concentricis pirofundis, regu- 

 laribus ; latere antico brevi ; latere 2)ostico sul- 

 angulato, truncato ; margine dorsali rectiiisculo vel 

 subrotundatim declivi ; margine interno niterdum 

 denticidato. 



The grooved Astarte. Shell subquadrate or orbi- 

 cularly subtrigonal ; concentric ridges deep, 

 regular ; anterior side short ; posterior side some- 

 what angular, truncated; dorsal margin rather 

 straight, or somewhat roundly sloped ; inner 

 margin sometimes denticulated. 



November, 187-1. 



