24(i DR. A. GU.NTHER ON NKW AMKRICAN FISHES. [Mar. 26, 



root of the veiitrals. Caudal fin slightly forked. Scales slightly 

 striated at the base, the lateral line being visible on the eight an- 

 terior scales. Uniform olive-coloured ; the middle caudal rays 

 black. 



Three examples, 2| inches long, were collected by Mr. Bartlett on 

 the Huallaga and at Xeberos. 



AnACYRTUS AFFINIS. 



D. 11. A. 55. L. lat. 80. 



Upper and lower jaws on each side with a pair of short conical 

 tooth-like processes directed forwards and outwards. Intermaxillary 

 teeth in two irregnlar series, those of the mandible being in a single 

 series, two pairs of them larger than the rest, canine-like. Maxillary 

 with four or five distant short conical teeth. Back much elevated, 

 the profile on the nape being deeply concave. The height of the 

 body is contained twice and two-thirds in the total length (without 

 caudal), the length of the head four times. Lower jaw considerably 

 shorter than the upper ; maxillary not extending to the vertical 

 from the front margin of the eye. Suborbital touching the lower 

 prseopercular limb, slightly and irregularly striated. The diameter 

 of the eye is equal to the width of the interorbital space, or to the 

 length of the snout, and two-sevenths of that of the head ; it is 

 placed immediately below the upper profile. The humeral process 

 in front of the pectoral terminates in an obtuse point behind, with- 

 out projection in front. Origin of the dorsal fin opposite to that of 

 the anal, rather nearer to the end of the snout than to the root of 

 the caudal. Pectoral extending beyond the vent, ventral beyond 

 the origin of the anal. Caudal forked. Humeral and caudal spots 

 more or less indistinct ; a narrow silvery band along and above the 

 lateral line. 



Two examples, 4 inches long, were collected by Mr. Bartlett on 

 the Huallaga. 



Anacyrtus (Cynopotamus) amazonum. 



D. II. A. 40. V. 8-9. L. lat. 110. 



The height of the body is contained twice and two-thirds in the 

 total length (without caudal), the length of the head thrice and 

 three-fourths. Upper profile deeply concave on the nape, the back 

 being much elevated. Abdomen not compressed, but with a median 

 ridge from behind the ventrals. The intermaxillary teeth are of 

 three sizes, viz. : — 1, a pair of large canine teeth in front of the jaw, 

 standing close together, and a second similar tooth close to the end 

 of each bone; 2, a series of small teeth between the canines men- 

 tioned ; 3, two smaller canines in a separate series inwards of the 

 small teeth. The maxillary is armed with a series of very small 

 teeth in its entire length. The teeth in the mandible are similar to 

 those of the intermaxillary, but rather stronger, and form a single 

 series ; they stand in the following order : — (first) two small teeth, 

 (secondly) a canine corresponding to the upper front canine. 



