84 BRITISH CAMBRIAN TRILOBITES. 



obliquity of the ocular ridge and the course of the facial suture, I suspect that only 

 his fig. 1 belongs to this species and that fig. 2 is a crauidium of Ot. pecten. 



Salter came to the conclusion that Ct. bisulcata was identical with the 

 Scandinavian species Sphserophthalmus alatus, but he was misled by Augeliu's 

 figure, which is totally unlike that form. His own figure is very different from 

 that of Phillips, but it may possibly represent a very imperfect specimen of the 

 species. 



Belt, 1 after examining the original specimens, concluded that Phillips's Olenus 

 bisulcatus and Salter's Olenus pecten, Olenus flag ellifer and Olenus alatus all belong 

 to one and the same species, but are not identical with Boeck's Sphaerophthalmus 

 alatus. According to him both Sphaerophthalmus (Otenopi/ge) bisulcatus and Sph. 

 tiu mil is (Sph. alatus) liave a minute pygidium with a long terminal spiue, and in 

 the case of Spli. bisulcatus the margin is serrated. 



Horizon and Localities. — -Upper Lingula Flags : Malvern; Moel Gron. 



3. Ctenopyge falcifera, sp. nov. Plate IX, figs. 5, G. 



Head quadrate, with the anterior lateral angles produced into spines. Glabella 

 rather less than twice as long as it is wide, narrowing very slightly forwards, 

 rounded in front, reaching the marginal furrow; one pair of glabellar furrows, 

 decidedly oblique, not meeting in the middle line ; neck-furrow shallow towards 

 the middle, well-defined laterally ; neck-segment with a median tubercle. Eyes 

 large, placed nearly in the middle of the cheek, at a distance from the glabella 

 about equal to the width of the latter ; ocular ridge long and oblique. Facial 

 suture cutting the anterior margin very obliquely, curving backwards to the eye, 

 bending abruptly outwards behind the eye and finally backwards to the posterior 

 margin, which it meets at a distance from the axial furrow about equal to one and 

 a half times the width of the glabella at its base. Fixed cheeks in front of the 

 eye about equal in width to the glabella, expanding behind the eye to one and a 

 half times that width ; free cheeks somewhat quadrate, marginate, the margin 

 produced into a distinct tongue in front of the fixed cheek, rather convex, with a 

 flattened area at the anterior external angle, this angle produced into a long 

 slender spine at first directed outwards and slightly forwards, but very soon bent 

 backwards, extending at least as far back as the posterior end of the thorax. 

 Hypostome tongue-shaped, but abruptly narrowed near the distal extremity, an 

 oval convex elevation forming the central part of the quadrate proximal portion. 



Thorax of nine or more segments, almost uniform in width up to the eighth 

 segment. Axis rather less than the pleural in width, with a median tubercle on 

 each segment. Pleurae straight, horizontal except close to their extremities, which in 



1 Geol. Mag., vol. v (1868), p. 10. 



