RAYMOND AND BARTON: AMERICAN SPECIES OF CERAURUS. 537 



cephalon is roughly semicircular, and about 0.45 as long as broad. 

 The glabella is very convex, expanding forward and reaching the 

 frontal margin. The expansion is about 1 mm. in 4. The frontal 

 lobe and the first pair of glabellar lobes are much more convex than 

 the posterior ones and compose about two thirds of the glabella. 

 There are three pairs of glabellar furrows; of these, only the posterior 

 pair are deeply incised. There is further a slight constriction running 

 backward from the inner end of each of these two furrows to the neck- 

 furrow. The fixed cheeks are very convex, highest at the eye, and are 

 separated from the glabella by deep dorsal furrows. The free cheeks 

 are apparently small. The eyes are situated far forward on the cheeks 

 and are nearer the glabella than the posterior margin of the cephalon. 

 The distance of the eye from the posterior margin of the cephalon is 

 about 0.5 the length of the glabella. A faint eye-line is present. 

 The neck-furrow is narrow and moderately deep. The whole cephalon 

 is surrounded by a convex border which is rather wide on the cheeks, 

 but very narrow in front of the glabella. The cephalon is covered with 

 scattering pustules and the cheeks are in addition thickly indented 

 with small pits. On the glabella, three pairs of pustules, two on the 

 frontal lobe and one on the first segment are more strongly developed 

 than the rest of the pustules. Of these, the second pair are the largest 

 and resemble a pair of short, heavy, horn-like spines. 



Remarks. — In the general appearance of the cephalon, barring the 

 glabellar spines, C. bispinosus is similar to C. dentatus and to C. 

 pleurexanthemus. In size, however, it is nearer the former than the 

 latter, while the reverse is true with regard to the position of the eye 

 and the eye-lines. The eyes are, however, slightly farther out and 

 forward than in C. pleurexanthemus. C. bispinosus is most readily 

 distinguished from the other species by the presence of the thick short 

 horn-like spines on the crest of the frontal lobe and by the rapid ex- 

 pansion of the glabella. This species is known only from a single 

 specimen, collected near Ottawa, by Mr. J. E. Narraway, in whose 

 collection the holotype now is. 



There was also found the larger part of a free cheek, which may 

 possibly belong to this species. The cheek is roughly triangular, 

 with a curving edge, and is separated from the border by a deep narrow 

 groove. The cheek is slightly convex and is covered with deep pits 

 and small spinules. The facial suture runs backward from the 

 anterior in a gentle curve, curves about the eye, and again gently 

 curving, runs outward to the border. The border is broad, convex, 

 and covered with coarse granules. The animal to which this cheek 



