EAST COAST MARINE SHELLS 



51 



lines of equal intensity, forming beads at 

 their intersection, the concentric lines 

 becoming obsolete upon the posterior half, 

 becoming spinous at that end; internal mar- 

 gin serrate. Length 14 mm., height 14.5 

 mm. Depth range 18-164 fathoms. 



PI. 6S, Fig. 7 



Rhode Island to the West Indies 



Family Venerldae 



This family represents the culmin- 

 ation of bivalve evolution so far as a sin- 

 gle family is concerned. In beauty of col- 

 or and delicacy of pattern, variety of 

 sculptiire, wide distribution plus depth 

 range, they equal if not surpass all other 

 bivalve groups. 



The animals are fully as beautiful 

 as the shells "leading one to wonder wny 

 parts which are always covered by mud or 

 sand should develop such beauties." 



The Lascar crews of ancient Span- 

 ish galleons used certain Venus for trade 

 in the Orient and consequently erroneous 

 habitats were often recorded. The common 

 Venus, or hard-shelled clam, of our east 

 coast was used by the Indians for making 

 wampum and ceremonial belts. 



GENUS DOSINIA Scopoli 1777 



Animal with large foot, siphons 

 closely united. Valves of shell usually 

 compressed; ligament strong and placed in 

 groove; luniile small; sculpture usually 

 consisting of elegant concentric grooves; 

 epidermis thin and lustrous; color usually 

 pale, many of the species white. 



DOSINIA CONCENTRICA Born. Shell rotund, 

 partly compressed, white, grooved; umbones 

 prominent. Length 2 inches. 



A smaller shell than D. elegans, 

 more convex, sculpture less conspicuous on 

 center and base of shell; lunule much larg- 

 er. 



It is rather rarely found on the 

 Florida Keys. 



PI. 19, Fig. 6 



Florida Keys to Brazil 



DOSINIA DISCOS Reeve. The most compressed 

 of our east coast Doslnias, also distin- 

 guished by the finer and closer concentric 

 grooves. The darker yellowish-brown epi- 



dermis, often in shaded areas, is distinc- 

 tive. Hei'ght 2.5 inches. It Is a rare 

 shell. 



PI. 19, Fig. 2 



Cape May, New Jersey to Vera Cruz, 



Mexico; apparently absent from the 



Antilles 



DOSINIA ELEGANS Conrad. A handsome flat 

 shell with imiformly placed concentric 

 grooves. It is often confused with D. con- 

 centrlca. The warm off-shore water is its 

 favorite habitat. Double fresh shells are 

 often abundant on the Sanlbel beach. Length 

 2.5 inches. 



PI. 19, Fig. 1 



PI. 18, Fig. 3 



Cape Hatteras, North Carolina to 



Yucatan; West Indies 



GENUS TRANSENNELLA Dall 1883 



Shell small, with the general form 

 of Tivela; hinge with three cardinal teeth 

 in each valve, the middle left cardinal 

 bifid; an elongated lateral tooth on left 

 valve which corresponds to a socket in op- 

 posite valve; lunule defined; peculiar 

 sculpture upon inner margin of valves which 

 are tangentially grooved. 



One of the Pacific coast species 

 produces its young alive. 



TRANSENNELLA CONRADINA Dall. Surface shin- 

 ing, concentric lines not very pronounced, 

 crossed by finer radiating lines. Length 

 12 mm. 



PI. 19, Fig. 7 



PI. 26, Fig. 6 



St. Andrew's Bay, Florida to 



Florida Keys and northward to Palm 



Beach 



TRANSENNELLA STIMPSONI Dall. Shell white, 

 variegated with brown lines or spots; orange 

 or deep purple inside, particularly toward 

 middle of valves. Length 14 mm. 



Easily the handsomest member of the 

 genus. It lives in from 8-30 fathoms and 

 was first found off Egmont Key, Florida. 



PI. 26, Fig. 4 



Cape Hatteras, North Carolina to 



Egmont Key, west Florida 



