104 JOURNAL OF THE NEW JERSEY 



and gaping behind ; small, thin, often irregular in form ; pallial 

 sinus very wide, 



1, Cumingia tellinoides, Con. Shell equivalve, ovate-triangular, 

 rounded and tumid in front, pointed, compressed, warped and 

 slightly gaping behind ; thin and fragile ; stages of growth marked 

 by sharp, thin, raised ridges ; cartilage pit shallow and directed 

 slightly backward ; lateral teeth at both ends in the right valve^ 

 none in the left ; muscular impressions faint ; pallial sinus wide 

 and deep. Bluish white, glossy white within. L. 15 ; H. 11 ; 

 W. 5 ; U. J ; An. 120.° — Cape Cod and south. Common in shal- 

 low water. 



2. Semele, Schum. 



Shell rounded, subequilateral, umbones turned forward ; pos- 

 terior side slightly folded ; hinge teeth two in each valve, laterals 

 elongated, distinct in right valve ; external ligament short, inter- 

 nal cartilage long, oblique ; pallial sinus deep, rounded. 



i. Semele reticulata, Gmel. Shell orbicular, somewhat compres- 

 sed; umbones nearly central, slightly prominent; lunule small; 

 valves sculptured with fine thread-like concentric ridges the 

 spaces between them are (under a lens) finely radiately striated ; 

 interior cartilage cavity deep, fusiform, parallel with the anterior 

 slope. Yellowish-white. L. 30; H. 30; W. 11 ; U. i Virginia 

 and south. 



Family 22. PAPHIID£. 



Shell elongated, usually somewhat triangular, equivalve, closed; 

 cartilage in an internal cardinal pit. Siphons separated. 

 1. Ceronia, Gray. 



Shell oval- wedge-form, truncated behind; lateral teeth coarsely, 

 obliquely striate. 



1. Ceronia arctata, Con. Shell sub triangular, wedge-shaped, 

 thick and strong, the posterior part short, truncated, forming the 

 base of the wedge, closed ; hinge with a very deep cavity for the 

 cartilage; surface with occasional, concentric ridges; muscular 

 impressions distinct ; pallial sinus about the size of the posterior 

 impression. Covered with a golden yellow epidermis reflecting 

 a metallic lustre. L. 35 ; H. 25 ; W. 14 ; U. f ; An. 115°.— New 

 Y^ork and north. Common. 



Family 23. SOLENID/E. 



Shell elongated, gaping at both ends ; ligament external ; car- 



