CARBONIFEROUS FOSSILS OF IRELAND. 159 



Seminula RHOMBOIDEA. Pllil. SP. 

 Terebratula rhomboidea. Phil. Geol. York Terebratula rhomboidea. Phil. Pal. Fos. 



Sp. Ch. — Shell small, globose, rhomboidal ; marginal elevation very liigh, indented in the middle; length 

 and breadth equal. 



This small, wcll-mai'ked species is extremely constant in its characters ; the valves are perfectly smooth, 

 with the exception of the lines of increase ; the two valves are equally deep ; the depth of the two valves equals 

 half the breadth ; the broad elevation of the front is not perceptible on the smaller valve, which is convex, but 

 forms a very wide depression in the dorsal valve ; the elevation of the margin has a notch or indentation in 

 the middle, from which a small ridge runs througli the centre of the mesial depression in the dorsal valve, 

 and a small groove through the centre of the ventral valve towards the beak. Length six lines, width six lines. 



CRUSTACEA. 



AsTACUs ? Phillipsii. M'Coy. (PL XXIII. fig. 1). 



The very interesting fossil to which I have given the above name is, I believe, the first instance in which 

 any remains of the Macro urous Decapods have been found in the Irish Palajozoic strata; the specimen is from 

 the thin beds of limestone, intercalated with the slate of Hook Head, Waterford, where it was collected by 

 Mr. C. W. Hamilton, Secretary of the Geological Society, Dublin, in whose collection it is preserved. The 

 specimen consists of a short portion of the leg, the carpus, and the penultimate, or immoveable joint of the di- 

 dactyle hand or pincers, apparently of the right side ; the existence of a thumb or mobile finger, and a powerful 

 one, is proved by the marks of muscular attachment at the base of the penultimate joint, in the situation re- 

 quisite for moving it; so far as preserved, the length of the penultimate joint is one inch seven lines. The car- 

 pus is quadrangular, wider than long, width five lines ; length on the outside four lines, on the inside two lines. 

 The structure of the laminated shell, and of the ginglymoid joints, is still preserved. 



CaLYMENE (?) GRANULATA. Munst. 

 Calymene granulata. Miinst. Beitrage Calymene granulata. Phil. Pal. Fos. 



1^. Ch. — Cephalothorax, semicircular; surface minutely tuberculated ; glabella pear-shaped, very tumid; 

 cheeks small, triangular, convex ; eyes large, strongly reticulated ; pygidium obtusely rounded, lobes tumid, 

 nearly equal, each segment with a transverse row of granules. 



The specimens which have occurred of this species are aU imperfect, but seem identical with tlie Devo- 

 nian ones. This is obviously not a true Calymene. 



Calymene l^evis. Munst. 



Calymene laBvis. Miinst. Beitrage Calymene Isvis. Phil. Pal. Fos. 



The specimens referred to this species are very imperfectly preserved, they present, however, the same 

 remarkable parallelism of the sides of the body and subtruncate tail. I have not seen the liead. 



