26 



EAST COAST MARINE SHELLS 



Most of the species occur below 

 low tide mark. 



GENUS NUCULANA Link 1807 

 (Leda Schumacher 1817) 



NDCDLANA ACUTA CONRAD. Pointed Nut. Shell 

 inflated, oval, anterior end rounded and 

 somewhat drawn out, ridged from umbones to 

 anterior base; sculpture of well-defined 

 ridges which are mostly concentric; inte- 

 rior shining; color greenish olive. Length 

 9 mm. Depth range 2-225 fathoms. 



A variable little shell- It is 

 quite common in a few feet of water off 

 the Florida west coast. 



PI. 2, Fig. 2 



Off Martha's Vineyard to West 



Indies 



GENDS YOLDIA Muller 1842; 

 Portlandia, Morch 1853 



Shell compressed, posterior end 

 pointed; sculpture fine; covered with a 

 varnish-like epidermis; slightly pearly in- 

 side. 



YOLDIA LIMATULA Say. Shiny Yoldia. Very 

 smooth and shining; umbones near center; 

 twenty- two teeth on anterior, eighteen on 

 pointed side. Length 48 mm. or less. 



A very 

 beautiful shell, 

 living in mod- 

 erate depths. 

 It once was 

 plentiful in 

 Boston harbor. 

 The writer has 

 a series from Raritan Bay, New Jersey which 

 was dredged around the year 1875. It prob- 

 ably is extinct there now. 



The animal is very active and will 

 leap to an astonishing height, in this re- 

 spect exceeding the scallop (Pecten) shells, 

 Fig. 30-. 



PI. 2, Fig. 4 



Gulf of St. Lawrence to North Car- 

 olina 



YOLDIA SAPOTILLA Gould. Pale yellowish 

 green, translucent, thin, about rixteen 

 teeth on each side. Range 4-100 fathoms. 

 It lives chiefly off Cape Cod and 



Fig. 50 

 loldia limatuJa 



may be obtained by dredging or in the stom- 

 achs of fish. Length 23 mm. 



PI. 2, Fig. 5 



Labrador to North Carolina. 



Family Arcidae 



Foot of animal deeply grooved. 



Shell with numerous comb-like 

 teeth, arranged in a line following hinge 

 margin and upon each valve. It is a very 

 ancient family, there being many fossil 

 species. 



GENUS ARCA Linn6 1758 



Shell elongated, strongly ribbed 

 or cancellated; umbones separated by a 

 lozenge-shaped area for the ligament. I 



In India Area scaphula lives in 

 the Upper Ganges a thousand miles from the 

 sea. The largest species lives at Panama. 

 (Pacific.) , 



ARCA AURICULATA Lamarck (A. deshayesii 

 Hanley) . Eared Ark. Shell with about 

 twenty-seven strong rounded ribs which are 

 crossed by concentric threads; oblong in 

 shape, inflated; high umbones separated by 

 a narrow area; angle in front at hinge line; 

 color whitish with a silky-brown epidermis. 

 Length 65 mm.; height 45 mm.; diam. 45 mm. 



PI. 3, Fig. 8 



Florida Keys and West Indies 



ARCA CAMPECHIENSIS Gmelin. Environment 

 influences this species and its varieties 

 to a very marked degree. It is largest 

 and coarsest at Cape Cod. There Is di- 

 versity in the outline. The ribs on the 

 left valve are often narrower, flatter and 

 less conspicuous than upon the right. The 

 typical form is the rounded southern one. 

 No very sharp line should be drawn in sep- 

 arating the various races. The average 

 length is around 2 inches. 



PI. 4, Fig. 8 



Massachusetts to Texas 



ARCA CAMPECHIENSIS PEXATA Say. Combed 

 Ark. Oblong, vunbones large, pitted below 

 them; inside margin deeply scalloped; epi- 

 dermis shaggy. Length 2.25 inches. 



It is known locally as the "bloody 

 clam" on account of the red fluid which 

 exudes from the tissues when the shell is 



