PENTACEROS RICHARDSONI. 



lies in front of the caudal fin. Head compressed and conical ; lower jaw 

 longest; gape small and each jaw has a broad band of short criniform 

 teeth. Nostrils double, the hindermost the largest, and both situated rather 

 nearer to the eye than the nose. Eyes large. Head rather more than one- 

 fourth of the total length of the fish, being 5 J in a specimen measuring 21 

 inches. The surface of the head between the preoperculum and subor- 

 bital plates consists of rather small somewhat circular scales, elsewhere 

 of strong bony plates externally radiated with granular striae. Shoulder 

 plates radiated in the same manner, the uppermost very coarsely. The under 

 surface of the body in front of ventral fins is flat and formed somewhat like 

 the thorax of an Ostracion : behind these fins to anus keeled, and both these 

 parts together with the edge of back between hind head and origin of dorsal 

 fin covered with hard tubercular or subangular plates, placed side by side like 

 stones in a pavement ; the other parts of the body are covered with scales simi- 

 lar to what are found on fishes generally, only they are rather small, as com- 

 pared with the size of the specimen. Lateral line commences immediately 

 over the second scapular plate, ascends, forming an arch, towards the dorsal fin 

 and on its reaching a point, under the fifth ray, it proceeds parallel with the 

 base of the dorsal fin till near the last spinous ray, where it begins to descend 

 obliquely till it reaches about midway between the termination of the anal 

 and dorsal fins ; from thence it proceeds in a straight line to the caudal fin. 

 Dorsal fin very strong anteriorly; the spinous rays very robust, and all 

 longitudinally striated; the fourth, fifth, and sixth rays the longest, — the 

 first much the shortest : the soft portion of dorsal fin very short, and not 

 higher than the lowest portion of the spinous part. Pectoral fin, pointed, the 

 first ray spinous, but short and slender ; the fifth ray the longest. Ventral 

 fins small, and the first or spinous ray very large and longitudinally striated. 

 Anal fin with the spinous rays strong, the second the longest, and all striated; 

 the cartilaginous rays shorter than the spinous. Caudal fin posteriorly 

 straight, or the outer rays of each side in the slightest possible degree 

 longer than the middle ones. 



D. V; P. T V; Y.fr A.$; C. 16. 



Length of individual described, 21 inches. 



The only specimen of this Fish I have seen, was procured near to Cape Point, and was taken 

 by means of a hook in very deep water. 



