158 CLASS I. TROPIOPODA. ORDER II. UNIMUSCULOSA. 



PECTEN, Bruguiere. 



Testa rotundata, raro affixa, regularis, inaequivalvis, subsequilateralis ; val- 

 vis pectiniformibus, insequaliter auriculatis, raro paululum biantibus, 

 costis vel sulcis ad margines ab umbonibus divergentibus. Cardo 

 edentulus, linearis, ligamento tripartito, penitiis interno ; partibus 

 duabus lateralibus, elongatis, lineam cardinalem, rectam, sequenti- 

 bus ; tertia parte triangulari, crassa, solida, in fossula centrali 

 inserta. Impressio muscularis magna, sublateralis. Animal bysso 

 parvo interdum affixum. 



We have already stated, in our observations on Lima, that the genus 

 Pecten was proposed by Bruguiere for the purpose of distinguisbing 

 certain mollusks that had been previously arranged with the Ostreee. 

 They are commonly known by tbe name of the Scallops, but their original 

 and most popular title is that of the Combs ; les Peignes of the French, 

 Pectines of the Latins, and Krevec* of the Greeks. Their shells exhibit 

 a most vivid array of colours, and the upper valve is usually more beau- 

 tifully painted than the lower ; the umbones approximate without the 

 least indication of any disc or area, and in this respect they differ from all 

 others of the family. The Pectines are very numerous, and may be sub- 

 divided into groups or sections, according to the inequality of the ears and 

 of the valves : in some, both valves are flat ; in others, both are convex ; 

 and in others, again, one valve is flat and the other convex (vide PI. CXIII.) . 

 There appears to have been some difference amongst authors as to whether 

 the animal of Pecten is provided with a byssus ; Mr. Cuming informs us 

 that he has only found certain species of Pectines with a byssus, and it 



The Kreis of Xenocrates and Galen is said to be the Pecten maximus of modern au- 

 thors. 



