BIVALVES SPONDYLUS. 29 



cations or branchings, on the the contrary, are flat, jagged, 

 and patulous at their extreme terminations. Those Spon- 

 dyU that are spined, as the Gaedaropus, &c. are mostly 

 of one color, as orange-red, purple, white, brown, and 

 yellow; which colors, in fine specimens, are exceed- 

 ingly brilliant. 



Those which have branches or plaits, (as the Spondy- 

 lus Plicatus, &c.), have, on the contrary, a ground color of 

 either of the above-mentioned tints, and the ramifications 

 are left entirely white. 



In some instances there is a compound of coloring, as 

 white and brown, purple and white, &c. &c. which 

 gives the shell a pied or brindled appearance ; and in 

 others (especially those which have a tendency to being 

 foliated as well as branched) the upper valve is of one 

 color, as purple or brown, having the lower valve per- 

 fectly white. 



The Spondyli generally have unequal valves, the 

 lower one protruding nmch beyond the other, and which 

 not unfrequently terminates in a curved and lengthened 

 beak. 



The hinge is furnished with two recurved teeth, which 

 are very strong and articulate, and separated by a small 

 but deep hollow ; the inner margin is mostly crenulate, 

 and highly colored with orange or purple. Some of this 

 genus are surmounted with ears on each side the beaks, 

 similar to the manner of Escallops; others, on the con^ 

 trary, are perfectly earless. 



They are found adhering to rocks, corals, &c. in groups 

 more or less numerous, often forming large masses ; others 

 are also found attached to shells. They are to be met 

 with in the American, Indian, Mediterranean, and other 



