PODOPSIS. CONCHIFERA. 79 



flat, and opercular ; hinge without teeth ; a single muscular 

 impression in each valve ; animal unknown. 



The shells of this genus have long been known in a fossil state under the name 

 of Gryphites. Only one recent species is known. In Britain the fossil species have 

 been found in lias, oolite, and green sand, Lamarck conjectures them to have been 

 Pelagic shells. 



G. angulata, Lam. Shell oblong ovate, with three longitudinal ca- 

 rinated ribs below ; beak large., suboblique. 4 inches long. In 

 the Museum at Paris.- Lam. vi. 1. 198. 



FAMILY II. PECTINIDES. 



Ligament interior, or partly so ; shell in general regular, com- 

 pact, not foliaceous. 



The greater part of this family have the ligament internal, but in some this liga- 

 ment is discovered through an opening of the joint. Some fix themselves to marine 

 bodies by a byssus, while others are attached by their lower valve. They are in 

 general eared at the lateral extremity of the inferior margin, and in general have 

 strias or ribs radiated from the hinge. 



Gen. 15. PODOPSIS, Lam. 



Shell inequivalve, adhering by its inferior beak ; without ears ; 

 lower valve largest, convex, and with the beak projecting ; 

 hinge without teeth ; ligament internal. (Fossil.) 



Gen. 16. SPONDYLUS, Lin. 



Shell inequivalve, adhering, eared, rough, with unequal beaks ; 

 the lower valve with an external longitudinal groove, which 

 increases with age ; hinge with two strong teeth in each valve, 

 and an intermediate hollow for the ligament, communicating 

 at its base with the external groove ; ligament internal. 



The shells of this genus are rough, with subulate, tongue-shaped, or foliaceous 

 spines, always disposed in rows over the strias or longitudinal radiated ribs. They are 

 generally highly and variously coloured. The animal has the border of its mantle 

 furnished with two rows of short tentacula or filaments. 



S. gcederopus, Lin. Shell red above ; longitudinal striae small and 

 crowded, granulated, with from six to eight rows of tongue-shap- 

 ed coloured spines ; the smaller ones sharp, the others obtuse or 

 truncated. 2 inches in diameter. Inhabits Mediterranean sea. 

 Lister, pi. 206, fig. 40. 



S. Americanus, Lam. Shell white, golden purple at the base, lon- 

 gitudinally sulcated; the principal spines very long, lingulate, and 

 the apex subfoliaceous. American seas. Favanne, pi. 44, fig. B. 



S. regius, Lin. Shell rounded, ventricose, golden red, longitudi- 

 nally sulcated and ribbed ; ribs five or six, with large spines j and 

 the furrows with shorter and sharp ones. Inhabits Indian seas. 

 A rare and beautiful shell. D'Argenv. pi. 20, fig. G. 

 Fossil species of this genus have been found on the Continent at Turin and Grignon. 



Gen. 17. PLICATULA, Lam. Spondylus, Lin. 

 Shell inequivalve, without ears, narrowed towards the base; up- 

 per margin rounded and plaited; beaks unequal, entire; hinge 



