140 HYPOSTOMA PLECOSTOMD& 



flexures but possessed no appendices. Specimen in 

 the Collection eight inches in length to the extre- 

 mity of longest caudal ray. The whole body rough, 

 with rather minute hard studs, which are elongated 

 only on the extremity of the first pectoral ray and 

 on the centre of the plates. The plates covering the 

 body, with the exception of the abdomen (anterior 

 to the anal fin), are rounded, somewhat sub-angu- 

 lar, and on their posterior margins at first sight 

 appear crenated, from the points of the studs or 

 small spines projecting over. On the centre of the 

 three first rows of plates, counting from the dorsal 

 fin downwards, the points or studs are lengthened 

 and form three lines to the tail ; a fourth arises op- 

 posite the opercula, but is lost about two-thirds of 

 the length from the extremity. On the part of the 

 abdomen without plates, the studs are arranged in 

 parcels of irregular form, which gives the appear- 

 ance of a minute plating. The head in its form is 

 somewhat triangular ; on the snout there is a cen- 

 tral rounded ridge, which is lost between the nostrils 

 and eyes, but again becomes more prominent, run- 

 ning into the first plate upon the back in a rounded 

 point; from each nostril, above the eyes, there is 

 an elevated ridge, which by the form that it gives 

 to the sides of the head reminds us of the Gur- 

 nards; in every part it is closely covered with 

 minute studs, very slightly lengthened on the side 

 of the operculum. The mouth is triangular, and oi 

 smaller dimensions than in some of the other spe- 

 cies ; the teeth are also stronger, and are set in a 



