406 Prof. F. M'Coy on the Classification of 



mental furrows, except the first, on the lateral lobes, and by the 

 more pointed outline and narrow margin. 



Not uncommon in a Lower Silurian schist over the iron-works 

 at Tremadoc ; very similar in appearance to that at Pomeroy, co. 

 Tyrone, which afforded the species to Col. Portlock. 



(Col. University of Cambridge.) 



Griffithides meso-tuberculatus (M'Coy). 



Sp. Char. Cephalothorax 10 lines wide ; glabella widely pyri- 

 form, broadly rounded in front, gently convex and narrowing 

 posteriorly with concave sides, very minutely granulated, length 

 5 lines, width 4 lines ; cheeks triangular, flat, smooth ; eyes 

 large, reniform, very minutely reticulated, with a large convex 

 eye-lobe * connected with the base of the glabella by a small, 

 oblique, oval nucleus ; limb broad, convex, with nine or ten 

 imbricating striae, two-thirds concealed in front of the gla- 

 bella, ending posteriorly in acute spines as long as the glabella ; 

 neck-segment broad ; pygidium 6 lines long and 7^ lines wide ; 

 axal lobe 2 lines wide, cylindrical, slightly tapering, of sixteen 

 rings, each ornamented with about ten lengthened oval tuber- 

 cles ; lateral lobes depressed, of ten broad, flat divisions, each 

 having a fine impressed line running close to its posterior 

 margin, smooth to the naked eye, but with a strong glass one 

 or two rows of minute crowded granules are seen ; margin 

 wide. 



The axal lobe of the pygidium being strongly tuberculated and 

 the lateral lobes nearly smooth, distinguish the species from all 

 other carboniferous Trilobites I know of. It is allied to the 

 G. calcaratus (M'Coy) and G. longispinus (Portk.). 



Common in the shales of the carboniferous limestone of Der- 

 byshire. 



(Col. University of Cambridge.) 



Cryphaus Sedgwickii (M'Coy). 



Sp. Char. Cephalic shield subsemicircular ; glabella slightly cla- 

 vate, smooth, three segmental furrows on each side, the pos- 

 terior pair longest, turning backwards and inwards nearly to 

 the neck-furrow, inclosing a triangular space on each side 

 longer than wide, the width rather less than that of the undi- 

 vided portion of the glabella between their bases, the two an- 

 terior pair of furrows shorter; cheeks broad, gently convex, 

 closely and coarsely pitted : thorax, axal lobe very convex, narrow, 

 slightly tapering, nearly parallel-sided, smooth, of twelve seg- 



* Eye-lobe seems preferable to eye-lid fox the lobe covering the inner and 

 upper aspect of the eye. 



