476 Dr. A. Gunther on some neio Freshwater Fishes 



Callichthys armatus. 



This species belongs to the group with compressed head. 



Dorsal spine as high as the body, finely serrated behind ; 

 pectoral spine rather stronger but shorter than 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. 



Xeberos and Huallaga. 



Chcetostomus Fordii. 



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

 of the total (without caudal). Eye small, one-eighth of the 

 length of the head, and two-fifths of the width of the inter- 

 orbital space, which is rather flat. 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 brown flat apex. 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. Pectoral spine strong, extending to the second third 

 of the ventral fin, covered with short hooks. 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. Brownish black ; most of the scutes have a 

 round bluish-white dot at the base ; lower parts with nume- 

 rous similar but more distinct white dots. 



Surinam. 



Head and trunk much depressed and flattened. The length 

 of the head is rather more than one-third of the total (without 

 caudal) ; the diameter of the eye is one-fifth of the length of the 

 head, and two-thirds of the width of the interorhital space. The 

 margin of the snout is covered with short bristles ; interoper- 

 culum with a bundle of about eight similar bristles, the longest 

 being only half as long as the eye. The lower side of the 

 head, thorax, and belly entirely naked. Pectoral spine ex- 

 tending to the second third of the ventral, and rather rough ; 

 eleven scutes between the anal and caudal fins. Scutes with 

 numerous strige, each stria composed of numerous very small 

 spines. Brown ; each scute with several round, very small, 

 whitish dots ; dorsal and caudal rays with a series of similar 

 dots, the interradial membrane being immaculate. 



Surinam, 



Chcetostomus 



Head but slightly depressed, rather longer than broad, its 



