MONOGRAPH OF THE GENUS 



VENUS. 



Fam. Yeneridse. 



Char. Gen. Testa sequivalvis, insequilateralis, plerumque ovalis 

 seu orbicularis; imprcssionibus muscularibns duabus subrenifor- 

 mibus ; pallii impressione plerumque postice plus minus sinuata ; 

 ligamento externo ; lunula impressa ; cardine deutibus duobus et 

 tribus cardinalibus. 



In the Ci/therace there is a lateral tooth near^ and anterior to, 

 the diverging cardinal teeth ; tliis is wanting in most of the true 

 Veneres, and although in the orbicular group, which has been 

 separated under the generic name " Bosina," a shght indication 

 exists of a similar tooth, it is so rudimentary as to be almost 

 imperceptible. The genus includes some very different-looking 

 groups, which yet pass so gradually into each other as to render 

 a division into distinct sections impracticable. All the species 

 however, from V. puerpera to V. gallina, have a crenulated inner 

 margin, and the few from V. striata to V. aqiiilatera have it 

 smooth. 



1. Venus puerpera (pi. clii. f. 1, 2), Linn. Mantissa, 

 p. 545. Venus reticulata. 



y. testa ponderosa, ventricosa, subrotundata, sulcis planulatis 

 radiantibus et costellis concentricis antice crassiusculis submonili- 

 feris erectis postice sublaminatis decussata; pallide fulva, fusco 

 variegata et purpureo (postice prsecipue) obscure radiata, intus 

 postice purpurea; latere postico magno, subtruncato; marging 

 dorsah elevato, arcuato, longitudinaliter plicato ; latere antico 

 brevissimo, umbonibus depressis; lunula magna, linea impressa 

 circumscripta ; margine ventrali intus crenulato. 



Tliick, ventricose, rather rounded, Avith flattened radiating rib- 

 lets, crossed by rather thick concentric ribs, which are inclined to 

 be laminar at the hinder part of the shell, and beaded or scalloped 



4 Y 



