28 GENERA OF SHELLS. 



The veneres are amongst the most beautiful of the 

 conchiferse. They are not distinguished by their gen- 

 eral form from the cytherese, but are more commonly 

 transverse than orbicular. The middle cardinal tooth, 

 which is often bifid, is straight, whilst the lateral are 

 oblique and diverging ; a few species have all the car- 

 dinal teeth straight. They are found in all seas, and 

 live in the sand, a short distance from the shore. 



I. Internal margin of the valves crenated or den- 



TATED. 



(a.) Shells with lamellar striœ. 



V. puerpura, reticulata, pygmaea, corbis, crenulata, dis- 

 cina, verrucosa, rugosa, câsina, crebrisulca. plicata, cancel- 

 lata, subrostrata, — castanea. inequalis, elevata, prseparca. 

 (h.) Shells icithout lamellar striœ. 



V. granulata, pectorina, marica, cingulata, cardioides, 

 grisea, elliptica, Dombeii, mercenaria, lagopus, gallina, gal- 

 linula, pectinula, sulcata. 



II. Internal margin of the valves very entire. 



V. lamellata, exalbida, rufa, dorsata, hiantina, crassisulca, 

 corrugata, Malabarica, papilionacea, adspersa, punctifera, 

 turgida, litterata, sulcaria, textile, texturata, geographica, 

 rariflamma, decussata, pallastra, glandina, truncata, retifera, 

 anomala, galactites, exilis, scalarina, Scotica, aurea, vir- 

 ginea, marmorata, ovulea, laterisulca, callipyga, opima, nebu- 

 losa, phaseolina, carneola, florida, petalina, bicolor, flori- 

 della, catenifera, pulehella, sinuosa, tristis, rimularis, vul- 

 vina, vermiculosa, flammiculata, conularis, strigosa, aphro- 

 dina, Peronii, aphrodinoides, elegantina, flammea, undulosa, 

 pumila, ovata, inquinata — grata, notata. 



Venericardia. Shell equivalve, inequila- 

 teral, suborbicular, generally with longitudinal 

 radiating ribs ; cardinal teeth two, oblique, in- 

 clining to the same side. 



