MOLLUSCA 137 



Several varieties of the species have been 

 described. 



Yoldia limatula Say 



PLATE XV. Fig. 3 



Hinge and color somewhat similar to Nucula but 

 larger (up to 2 inches) and with one end tapering. 

 Lives in shallow water in muddy associations. The 

 shell is rarely found on the beach but has been dredg- 

 ed in Delaware Bay, Barnegat Bay, etc. Range : Gulf 

 of St. Lawrence to North Carolina. 



Area campechiensis G-melin (Ark; Bloody Clam) 

 (A. pexata Say) 



PLATE XIV. Fig. 1 



One of the commonest shells of the New Jersey 

 beaches. The genus Area is characterized by the 

 long row of comb-like hinge teeth. A. campechiensis 

 has an oblong shell with its beak directed forward. 

 Radiating ribs are prominent and the shell is 

 covered with a hairy brown epidermis, which, how- 

 ever, is often removed before the shell is washed 

 upon the beach. Up to 3 inches in length. Lives 

 in both inland waterways and in shallow water 

 in the open ocean. Known from Massachusetts to 

 Yucatan, Mexico; its name is taken from the Gulf 

 of Campeche (Mexico) where it was first described. 



Area transversa Say (Ark; Transverse Ark) 



PLATE XIV. Fig. 5 



Similar to the above but elongate and with 

 beak more central and not directed forward. 



