230 



Pecten — continued. 



asper. . suborbicular, convex on both sides ; twenty to twenty- 

 two rays, longitudinal, imbricated, squamous, rough, di- 

 vided by grooves. . 3j inches. 



benedictus. . inequivalved, upper valve plano-concave, lower very 

 convex ; twelve to fourteen flat rays, distinct, transversely 

 striated. 



clongatus. . ovato-oblong ; twenty-six to thirty rays, thin, un- 

 equal, subdenticulated. . 3 inches. . Mons. 



subacutus. . longitudinal, ovately wedge-form ; twenty-four close, 

 equal rays, sharp on the back. . 1|^ inch. 



phaseolus. . very small, oblongo-trigonal ; lower valve bowed in- 

 wards ; rays small, close, striaeform, equal. . f inch. . 

 Coulaines. 



eequicostatus. . unequal valved, trigonal, upper valve flat ; under 

 valve tumid, bowed inwards ; twenty- eight to thirty rays, 

 close, equal, smooth. . Mons. 



versicostatus. . unequal valved, trigonal ; upper valve flat ; under 

 valve tumid, bowed, curved inwards ; numerous close rays, 

 some remote, others more raised. . Mons. 



costangidaris — unequal valved ; lower valve bowed, curved in- 

 wards ; four large anguliform, longitudinal, grooved rays. . 

 Decize. 



orbicularis. . suborbicular, depressed, rather convex, no rays, 

 striae transverse, concentric. . Coulaines. 



discors. . subinequivalved, roundedly trigonal, rays ten, fine 

 transverse rugse on the other valve. . Chaufl"our. 



palmatus. . ovato-rotundate, five or six faint rays ; one ear very 

 large. 



lepidolaris. . ovato-rotundate ; with twenty squamoso-imbri- 

 cated rays ; squamse small, disposed in many rows, . 

 1 inch. . Boutonnet. 



sieniensis. .s,uborhic\ila.r, convex on both sides; strice longitu- 

 dinal. . 1| inch. 



striatulus. . suborbicular, convex on both sides ; ten or twelve 

 thick rays ; interstices longitudinally striated. . 1^ inch. 



iruequicostalis. . suborbicular, twelve to fourteen unequal rays, 

 with the interstices longitudinally striated. . 1 j inch. 



scutularis. . ovato-rotundate, subdepressed, small ; twenty to 

 twenty-five equal rays, rather sharp on the back. . f inch 

 . . Bourgogne. 



scabrellus. . suborbicular, with fifteen sulcated rays, squaraously 

 denticulated ; ears unequal — 1 j inch. . Italy. 



plebeius. . suborbicular, with twenty-five to thirty angulato- 

 sulcated rays ; sides squamosely scabrous. . Grignon. 



pumilus. . very small, roundedly ovate ; ten or twelve rays. 



squamula. . very small, orbicular. 



Plicatula. 



angulosa. . oblong, wedge-formed ; with large unequal folds ; 

 backs angular, squamous. . 2 inches. 



