304 CARL H. EIGENMANN AND WILLIAM RAY ALLEN. 



MONOCIRRHUS MIMOPHYLLUS Eigenmann & Allen spec. nov. 



15715, I., 3, 44, 47, and 51 mm. long to base of caudal (65 mm. 

 over all). Brooks near the Rio Itaya, Iquitos. Collected by 

 Dr. W. R. Allen. 



Evidently closely allied to M. polyacanthus Heckel, if distinct. 

 In M. polyacanthus the caudal is said to be emarginate, the lateral 

 band is said to run through the lower half of the tail, and the 

 edge of the dorsal, anal, and tip of the ventrals are said to be 

 blackish, the end of the caudal white. 



Head 2.5; depth 1.92; D. XVI or XVII, 13; A. XII or 

 XIII, 12 to 14. 



Greatly compressed, the snout very sharp, the chin projecting, 

 with a goatee barbel; the two rami of the mandible in contact 

 below, equal in length to the head behind the anterior nares; 

 maxillaries equal to snout and eye; premaxillaries greatly pro- 

 tractile; eye 1.5 in snout, 4 in the head, about .8 in the inter- 

 orbital; opercular spine on a line between the upper margin of 

 the orbit and the upper margin of the caudal peduncle. Profile 

 between snout and occiput concave; gill-membranes somewhat 

 united, entirely free from the isthmus, entirely hidden by the 

 rami of the mandible. 



Tongue very long and slender, rod-like, the free portion about 

 as long as the eye, its tip soft, curved up and slightly cupped; 

 premaxillary spine extending far beyond the eye, equal to the 

 length of the mandible; mandible with one, in part two series of 

 minute, recurved teeth; premaxillary with a single series of 

 teeth on the sides, a triangular patch of teeth at the tip; no 

 teeth on roof of mouth. 



Pectoral broad, its length about 3 in the head, soft-rayed; 

 distance between tip of the snout and origin of the dorsal a little 

 more or a little less than 2 in the length without caudal ; base of 

 the spinous dorsal 2 in the length; base of soft dorsal about one- 

 fifth of the length of the spinous dorsal; caudal rounded, equal 

 to snout and eye or a little shorter; origin of anal and third 

 dorsal spine equidistant from tip of snout ; base of spinous portion 

 of the anal about three in the length; base of soft part of anal 

 a trifle longer than base of soft dorsal; ventrals reaching origin 

 of anal, their inner ray adnate. First ray stout and spinous. 

 Cheeks, opercle, and top of head to tip of snout scaled ; preorbital 



