CARBONIFEROUS FOSSILS OF IRELAND. 93 



appears to mo that Professor Phillips's figure 19, which he refers witli a doubt to the P. dissimilis of Fleming, 

 belongs rather to this shell ; the two species are very distinct. Length one inch two Hnes, width one inch 

 four lines. 



Pecten filatus. M'Coy. (PL XIV. fig. 10). 



Sp. Ch. — Elongate, ovate, convex ; ears distinct, square, unequal; surface nearly smooth, with very fine, 

 longitudinal, thread-like stria;. 



This species is remarkable for its nearly parallel, wire-like stria3, which are scarcely visible to the naked 

 eye ; the form is regularly ovate ; the ears deeply di\-ided from the body of the shell, large, unequal, rectangu- 

 lar. Length ten lines, width nine lines. 



Pecten FLABELLULUM. M'Coy. (PL XV. fig. 17)- 



Sp. Ch. — Orbicular, flattened; surface gently undulated by faint, irregular, radiating, rounded plaits, 

 obsoletely striated longitudinally ; a few distant, sharp, radiating ridges extend from the beak about half way 

 to the margin. 



This beautiful shell is in no danger of being confounded with any other ; it resembles an expanded fan, the 

 surface being marked with broad, nearly obsolete, longitudinal folds, and about eight or nine slender, radiating 

 ridges extending half way from the beak ; under the lens the siuface appears very finely and obscurely striated. 

 Length one inch, width about two lines more. 



Pecten FLEXuosus. M'Coy. (PL XVIIL fig. 1). 



Sp. Ch. — Shell ovate, nearly orbicular, with about forty-five iiTegular, rounded, flexuous, radiating ribs; 

 ears small, falcate, pointed, sharply striated, parallel with the outer margin. 



The only specimen I have seen of this species is but indifferently preserved ; the surface is slightly convex; 

 the ribs vinarmed, radiating in a waved or slightly irregular manner ; only one ear remains, small, and somewhat 

 falcate. Length two inches, width two inches two lines. 



Pecten Forbesii. M'Coij. (PL XV. fig. 20). 



Sp. Ch. — Orbicular, convex; surface marked with strong, close, radiating ribs, alternately larger and 

 smaller, cancellated by sharp, concentric ridges ; ears small, imequal, one square, undefined from the body of 

 the shell, the other small, narrow, rounded, marked with a few radiating ridges, and strong stria parallel to the 

 margin. 



This little species is allied to the P. arenosus, Phil., but is more orbicular, and the concentric striaj 

 are coarser and farther apart ; the ears also are entirely difierent in form. Length five and a half lines, width 

 six lines. 



Pecten GiBBosus. M'Coy. (PL XVIII. fig. 5). 



Pecten gibbosus. M^Coy. In Catalogue Gaol. Soc. Dublin. 



Sp. Ch. — Shell orbicular, very convex, smooth, marked by a few concentric lines of growth; ears nearly 

 equal in length, posterior ear undefined, rectangular, anterior ear narrow, deeply divided from the body of the 

 shell, truncate at the extremity. 



This little species is almost globular ; the small, lengthened ear is perfectly flat and distinctly separated 

 from the body of the shell. Length seven lines, width the same. 



Pecten granosus. Sow. 



Pecten granosus. Sotc. Min. Con Pecten granosus. Phil. Geol. York. 



Sp. Ch. — Nearly orbicular, wider than long, convex; ears small, unequal, surface with about thirty tuber- 

 culated ribs, between each of which is a smaller, nearly smooth one. 



2 A 



