56 



EAST COAST MARINE SHELLS 



Astarte but is more related to Gemma on ac- 

 count of being viviparous. The genus is 

 entirely American in distribution. 



PARASTARTE TRICUETRA Conrad. A genuine 

 Florida type, confined to the peninsula, 

 both recent and fossil. Length 3 mm. 



PI. 21, Fig. 9 



Palm Beach Inlet, east Florida, to 



the Florida Keys and northward to 



Cedar Keys, west Florida 



Family Petricolldae 



Shell elongated, rounded in front, 

 narrowed in rear; hinge almost toothless; 

 ligament external. 



GENUS PETRICOLA Lamarck 1801 

 (STONE DWELLERS) 



PETRICOLA LAPICIDA Gmelln. The juvenile 

 specimens are characterized by a zigzag 

 striation to which are added in the adults, 

 on the posterior end, coarse radiating 

 ridges. Length 20 mm. 



It bores in coral and is well dis- 

 tributed in the Florida Keys. 



PI. 25, Fig. 11 



South Carolina to the West Indies 



SUBGENUS PETRICOLARIA Stoliczka 1870 



PETRICOLA PHOLADIFORMIS Lamarck. Shell 

 chalky white, sharply rounded in front, 

 covered with raised radiating lines and 

 ribs; each valve equipped with two teeth, 

 the one in left valve deeply cleft. Length 

 2.25 inches. 



Animal with two tubes or siphons 

 extending from rounded end of shell and 

 united at their bases. The orifice of one 

 of these is used for imbibing water. 



This shell is usually found boring 

 into hard clay on marshes at lowtide mark, 

 frequently in large nimbers. It has been 

 taken at Far Rockaway, New York City. 



PI. 27, Fig. 2 



PI. 25, Fig. 6 



Prince Edward Island to V.'est Indies 



PETRICOLA PHOLADIFORMIS LATA Dall. Shorter 

 and broader than the preceding; radiating 

 lines more numerous, about sixteen in num- 

 ber, not so much raised; teeth shorter and 

 grooved, large middle tooth folded. Length 

 1.75 inches. 



PI. 25, Fig. 6 



Maine to South Carolina 



GENUS RUPELLARIA Fleuriau 1802; 

 Choristodon Jonas 1844 



RUPELLARIA TYPICA Jonas. Shell well 

 rounded in front, moderately produced and 

 gaping in rear; about forty strong radiat- 

 ing ribs which are finer tov.'ard the front 

 and rear of the shell, growth lines between 

 the ribs undulating, margins irregularly 

 crenulate, one strong upright tooth in 

 right valve. Length 25 mm. 



This species bores in soft rock 

 between tides and is not rare. There is a 

 colony inside the N. Inlet at Palm Beach 

 and in Biscayne Bay, off Arch Creek, Flor- 

 ida. 



PI. 25, Fig. 7 



North Carolina to Florida; West 



Indies 



GENUS CORALLIOPHAGA Blainville 1624 

 (CORAL DWELLERS) 



CORALLIOPHAGA CORALLIOPHAGA Gmelin. Shell 

 thin, cylindrical, gaping slightly behind; 

 two hinge teeth in each valve, also a pos- 

 terior tooth; pallial sinus wide and shal- 

 low. 



It lives in the burrows of other 

 mollusks. Often several dead specimens to- 

 gether with the original inhabitant are 

 found in a burrow. Length 1.5 inches. 



PI. 25, Fig. 14 



West coast of Florida to Texas; 



West Indies; Mediterranean 



Family Tellinidae 



Shell compressed, rounded in front, 

 angular and slightly folded posteriorly; 

 ligament external, prominent. Animal with 

 slender diverging tentacles, foot broad. 

 On account of the great diversity and scope 

 of the family it is a difficult one to de- 

 fine in a few words. There are about five- 

 hundred species known, some living at con- 

 siderable depths. Tellina often almost ap- 

 proximates Venus in beauty of coloring and 

 form. 



GENUS TELLINA Linng 1799 

 (TELLIN SHELLS) 



TELLINA INTERRUPTA Wood. Shell oval or 



