44 



EAST COAST MARINE SHELLS 



shell from others. Range 3-100 fathoms. 

 PI. 13, Fig. 6 

 PI. 73, Figs. 11, 13 

 Massachusetts to Florida 



Family Carditidae 



Hinge with a short, strong, erect 

 tooth under umbones and an oblique one ex- 

 tending along margin. 



GENDS CARDITA Bruguiere 1792 



CARDITA FLORIDANA Conrad. Shell with sev- 

 enteen to eighteen heavy ribs with bluntly 

 raised scales upon them; ligament external; 

 color yellowish white, young shells touched 

 with purple. Length 1 inch. 



This species lives mostly in pro- 

 tected bays. It is quite common upon 

 Florida beaches. 



PI. 13, Fig. 12 



Florida to Texas 



CARDITA GRACILIS Shuttleworth. A long and 

 narrow shell which is rarely found on the 

 beaches. 



PI. 11, Fig. 9 



Tampa Bay to West Indies 



GENOS VENERICARDIA Lamarck 1801 



Shell roimded-trigonal, radial 

 ribs the strongest, the ribs often beaded 

 especially in the young; hinge with two 

 cardinal teeth in the left and three in 

 the right valve. 



VENERICARDIA BOREALIS Conrad. Shell thick; 

 about eighteen rounded radiating ribs with 

 narrow spaces between; epidermis brown or 

 black; margin crenulated; lunule small and 

 deep; ligament small and sunken; interior 

 white. Length 1 inch. Range 3-250 fath- 

 oms. 



PI. 13, Fig. 13 



PI. 73, Figs. 9, 10 



Labrador to Cape Hatteras, North 



Carolina 



VENERICARDIA TRIDENTATA Say. Shell minute 

 but ponderous, thick, about eighteen con- 

 vex ribs crossed by elevated concentric 

 lines; margins inside deeply crenulated; 

 two diverging teeth, with large cavity be- 

 tween, in one valve; in other valve a sin- 



gle triangular tooth which fits into the 

 cavity opposite. Length 6.5 mm. Range 

 36-124 fathoms. 



Fresh examples are not uncommon 

 upon the Florida beaches. 



PI. 14, Fig. 5 



North Carolina to Florida; Gulf of 



Mexico 



Family Chamidae 



Shell inequi valve, irregular, 

 thick, attached to some solid object or 

 its own kind; the free valve on right or 

 left side, fixed valve more convex and of 

 greater size than the other; hinge thick, 

 with anterior groove and with an oblique 

 arched cardinal tooth and a straight fur- 

 row. 



The shell consists of three layers; 

 external layer with oblique lines of growth; 

 middle layer of opaque white; inner layer 

 translucent and membranous. 



GENUS CHAMA Linn§ 1758 



CHAMA MACEROPHYLLA Gmelin (C. macrophylla 

 Gmelin) . Shell with many prominent folia- 

 tions which are pointed and sometimes com- 

 pressed; color varying from purple to yel- 

 low; interior margins conforming to exte- 

 rior color; central and tooth areas whitish; 

 margin of shell minutely crenialated. 



This species is often gregarious, 

 several individuals being fastened togeth- 

 er. A chisel and hammer are handy in sep- 

 arating them from rocks. Finely colored 

 individuals live near Jupiter Inlet, 

 Florida. Length 43-65 mm. 



PI. 14, Fig. 2 



East Florida; Tampa, Florida to 



Curacao, West Indies 



CHAMA CONGREGATA Conrad. Usually a small- 

 er form than the preceding, also with fin- 

 er foliations. Length 21 mm. 



An inhabitant of Upper Biscayne 

 Bay, Florida, where it may be found under 

 stones. 



PI. 14, Fig. 4 



Cape Hatteras, North Carolina to 



Yucatan 



CHAMA SARDA Reeve. Shell small, attached 

 valve deepest of the two; surface with wavy 

 scales; upper valve often with reddish rays 



