CARBONIFEROUS FOSSILS OF IRELAND. 51 



Sangutnolites undatus. Portk. sp. 



Sanguinolaria undata. Portk. Geol. Rep. 



Sp. Cli. — Transversely elongate, widtli about three and a half times the length; depressed; posterior end 

 obliquely truncated, broad ; anterior end very narrow, rather lengthened, rounded ; surface regularly marked 

 with strong, equal, subangular, concentric ridges, continuing strongly defined across the whole shell ; interme- 

 diate spaces broad, concave, smooth. 



This species differs from the Sanguinolites Iriduioides, M'Coy, in the strong, prominent ridges being con- 

 tinued equally from the posterior end, across the entire body of the shell to the anterior end, with a very trifling 

 diminution in size, and without increasing perceptibly in number ; the ridges are narrower, more equal, and 

 the intervening species broader and smoother, than in that shell ; they are also bent more angularly at the 

 posterior end ; the anterior end is much narrower in the present species. 



Anatina. Lam. 

 Gen. Ch. — Shell very thin, inequi valve, inequilateral, ti-ansverse; hinge, with a spoon-shaped process, 

 containing the cartilage, and a small, lengthened, testaceous appendage. 



Anatina ATTE>ruATA. M' Coy. (PI. VIII. fig. 6). 



Sp. Ch. — Transversely ovate, attenuated posteriorly; gibbous, smooth; beaks prominent, anterior end 

 roimded ; front margin very convex. 



This curious fossil and the next are referrible, with tolerable certainty, to the genus Anatina, not only from 

 the excessive thinness of the shell and external form, but from the characteristic testaceous appendage to the 

 hinge, which is very frequently preserved in both species. — (It has been imfortunately obliterated from the 

 Plate during the preparation of the stone for printing.) The form of the present species is clavate, being 

 roimded, and very gibbous anteriorly, attenuated, naiTow, and compressed posteriorly, where it is also rounded, 

 but is slightly oblique ; the beaks are very large, but somewhat flattened at the tip ; the testaceous appendage 

 of the hinge is about two lines long, flat, very narrow, and dilated at the tip ; muscular impressions are distinct, 

 the anterior being rounded, oval ; the posterior one crescent-shaped, palleal impression sinuous. Length seven 

 lines, width ten lines. 



Ajstatixa deltoidea. J/'Co?/. (PI. YIII. fig. 7). 



Sp. Ch. — Subtrigonal, gibbous; anterior side large, rounded; front margin very convex; posterior side 

 compressed, broad, obliquely truncated, separated from the body of the shell by an obtuse ridge, extending from 

 the beak to the posterior-inferior angle ; surface smooth. 



This species is easily distinguished from the A. attenuata, M'Coy, by the shortness and breadth of the 

 posterior side, and also by its greater convexity ; the shell is excessively thin ; the appendage to the hinge is 

 about a line and a half m length, and one-fourth of a line in width, the sides are nearly parallel, truncated at 

 the tip ; muscular impressions large, crescent-shaped ; palleal impression sinuous. Length seven and a half Hnes, 

 widtli ten lines. 



Pandora CLAVATA. M'Coy. (PI. XI. fig. 2). 



Sp. Ch. — Transversely elongate, clavate, width twice and one-third the length; beaks small, close to the 

 anterior end ; anterior end short, rounded ; posterior attenuated, slightly recui-ved, trancated at the extremity ; 

 one valve very convex, the other flat; surface of both valves strongly striated transversely. 



Tliis interesting little shell has a slightly marked posterior ridge. Length three lines, width seven lines. 



