1868.] 



OR. A. GUNTHER ON NEW AMERICAN FISHES. 



2.31 



CalUchthys armatua. 



as the bodvi finely serrated behind ; pectoral spine r ither stronger 

 but shorter tliau that of the dorsal, longer than the head. Anal 

 spine shorter and more feeble than that of the adipose fin. Olive- 

 coloured (in spirits), the nine or ten anterior scutes with vertical 

 series of small blackish spots. 



Several examples, 2 and 2\ inches long, were collected by Mr. 

 Bartlett at Xeberos and on the Huallaga. 



Ch^tostomus fordii. (Plate XXI.) 



D. 1/8. A. 1/5. P. 1/6. V. 1/5. L. lat. 25. 



Head much depressed, elongate, its length being one-third of the 

 total (without caudal) ; snout broad and elongate, the distance of 

 the eye from the posterior end of the head being only two-fifths of 

 the length of the snout. Eye small, one-eighth of the length of 

 the head, and two-fifths of the width of the interorbital space, which 

 is rather flat. Occiput terminating in a low obtuse ridge. The 

 entire upper surface of the head is very rough, and covered with 

 minute spines ; the scutes with which the snout is covered are but 

 loosely united, so that this part is rather soft. Interoperculum 

 with about ten setiform spines, the longest being about as long as 

 the eye. Each jaw with six or seven stoutish teeth on each side ; 

 each of them has a lobe on its outer side, rather distant from the 

 flat apex. Lower lip not notched, with numerous papillae. Throat, 

 thorax, and belly naked. The first ray of the dorsal and anal, 

 and the upper and lower of the caudal, slightly thickened and 

 rough. Caudal lobes more or less produced. Pectoral spine 

 strong, extending to the second third of the ventral fin, covered 

 with short hooks. Ventral spine as long as that of the pectoral 

 fin, extending beyond the anal. Each scute of the body with a 

 series of three or four very prominent spines. Ten scutes between 

 anal and caudal, and eight between the two dorsal fins. Brown- 

 ish black ; most of the scutes with a round bluish-white dot at the 



