94 SYNOPSIS OF THE CHARACTERS OF THE 



This fine species is one of the largest of the genus found in the carboniferous limestone ; the ears extend 

 nearly the width of the shell, but are narrow. Length one Inch ten lines, width two Inches (frequently three 

 inches in length). 



Pecten granulosus. Phil. 



Pecten granulosus. Phil. Pal. Fos. 



Sp. Ch. — Obliquely ovate, lengthened, slightly convex ; ears large, distinct, nearly equal; surface reti- 

 culated with fine, equidistant, radiating and concentric strlse. 



This little species resembles a Lima in general form. It is easily distinguished from the other species by 

 the minute, equal reticulation of the surface. Length six lines, width four lines. 



Pecten Hardingii. M'Coy. (PL XV. fig. 18). 



Sp. Ch. — Ovato-orblcular, depressed ; eai's equal, square, radiated with about five or six equal ridges, 

 crossed by others of equal size, parallel with the outer margin; surface radiated with twenty-two strong, equal, 

 splnulose ridges, alternating with which are an equal number of much finer strlas, also spinulose ; intervening 

 spaces flat, smooth. 



This species is distinguished from the P. interstitialis, Phil., and P. intercostatus, M'Coy, by having only 

 one fine rib between each pair of large ones. Length six lines, width seven lines. 



Dedicated to Major Harding, who has so materially advanced the knowledge of the fossils of the Devonian 

 series. 



Pecten hians. M'Coy. (PI. XVI. fig. 6). 



Sp. Ch. — Longitudinally ovate, depressed ; ears small, unequal, a very large fold beneath the posterior ear, 

 forming a hiatus in the margin ; surface with very numerous, rounded, radiating ridges, alternately larger and 

 smaller, crossed by regular, concentric, imbricating strlaa. 



This shell Is rendered very remarkable by the large fold on the posterior side, which, probably, served to 

 allow the byssus attaching the shell to pass through ; the byssus, however, according to this view, must have 

 far exceeded the size usual in this genus ; the ears are very small for the size of the shell. Length two inches, 

 width two inches two lines. 



Pecten incrassatus. M'Coy. (PL XVI. fig. I ). 



.S}^. Ch. — Orbicular, convex; ears nearly equal, acute; about twenty -five thick, rounded, radiating ribs; 

 surface with fine, irregular, concentric wrinkles. 



This boldly marked shell Is easily recognized by its numerous, large, rounded ribs, most of which are con- 

 tinued distinctly to the beak ; they are separated by concave spaces, wider than themselves : the ears are sharply 

 striated parallel to the margin ; the body of the shell has very delicate, short, discontinuous, membranous, con- 

 centric markings, which become larger towards the margin, where they give the ribs a slightly nodulous cha- 

 racter. Length one Inch two lines, width one Inch four lines. 



Pecten inornatus. Phil. 



Pecten inornatus. Phil. Gaol. York. 



Sp. Ch. — Ovate, shghtly convex ; ears small, equal, nearly square; surface concentrically waved, with ob- 

 tusely rounded, smooth wrinkles. 



Tills species Is usually somewhat less than the P. ellipticus, Phil., from which It is distinguished by the 

 large, concentric wrinkles on the body of the shell. Length seven lines, width six lines. 



