﻿46 ME. E. S. COBBOLD ON TBILOBITES FBOM [Feb. I9IC, 



and the posterior branch would seem to have been likewise short 

 and direct. 



Test. — A small portion of the test is still visible in the right- 

 hand corner of the specimen ; it is almost smooth (? worn), with 

 very slight indications of punctae. 



Locality and horizon. — Comley ; from the uppermost band 

 of the grey limestone at the excavation, 200 yards south of the 

 quarry. 



MoHICANA CLAVATA, sp. nOV. (PI. VI, figS. 5-9.) 



Several fragments of this allied species have been found ; the 

 most complete of these [586, 582, 584] are figured in PI. VI. 



Ceaniditjm : Size — moderate ; length = from 8 to 12 millimetres. 



General form. — Doubtful. 



General convexity. — Moderate ; about the same as in 

 Mohicana lata, but with more relief of the features. 



Glabella. — Moderately convex ; slightly clavate ; length, about 

 three-fifths of the head-shield ; width doubtful ; distinct from the 

 occipital ring ; slight indications of two transverse furrows on the 

 posterior half of the glabella, not visible at the sides ; apex 

 rounded ; greatest elevation a little behind the middle of the length. 



Occipital furrow. — Entire; wide and shallow. 



Occipital ring. — A plain band, slightly wider than the base 

 of the glabella. 



Axial furrows. — Shallow, but sharply impressed ; slightly 

 sinuous ; well marked round the apex of the glabella. 



Fixed cheeks.— Wide (?) ; gently and evenly convex; most 

 elevated close to the glabella, and falling away in a fairly even 

 convex curve to the frontal limb and to the eye-lobe which stands 

 away horizontally. 



Eye-lobe. — Fairly large, distant from the glabella, not reaching 

 the posterior border ; situated opposite the middle of the head- 

 shield ; slightly rounded transversely ; with an impressed line 

 inside it ; not raised at its outer edge. 



Ocular ridge. — Just visible as a raised fillet across the cheek ; 

 continuous from the eye-lobe to the axial furrow. 



Postero-lateral limb. — Marked by a wide furrow ; some- 

 what curved, with the curvature convex backwards, and margined 

 by a raised rounded rim, which is strongly geniculated about half 

 way out. 



Frontal limb. — Gently convex; continuous with the cheeks ; 

 marginal rim not seen in any of the specimens. 



Facial suture. — ISTot seen. 



Test. — Under a strong lens the surface is seen to be beautifully 

 marked all over by closely-set minute punctas or pits, which have 

 no corresponding processes on the interior. It is estimated that 

 there are as many as 150 to 200 to the square millimetre, and that 

 the interspaces are about one and a half times as wide as the 

 diameters of the punctse. These interspaces have a continuous 

 level surface, and answer to Dr. Walcott's description and figure of 



