284 PROCEEDINGS OF THE ACADEMY OP 



they occupy the entire inferior half of the side. The second 

 does not enlarge till near the postcephalic plates, where two or 

 three occupy the upper half of the side. Longitudinal line con- 

 taining twenty-one. Those of the superior and inferior series are 

 angulate near the margin of the peduncle, and meet on the supe- 

 rior and inferior median lines by a straight suture. Thus these 

 faces form distinct but slightl}^ convex, narrow planes. Parietal 

 shield broader than long, postparietal large, its apex separated 

 from D. I. by two cross-shields, the first wider. A large shield 

 on each side the postparietal. The whole of this region swollen, 

 greatest width of head at the sieve. 



Orbit three times in head, twice in interorbital width; head 3.5 

 times in length, without caudal fin ; depth 4.5 times in same. 

 Caudal fin well developed, deeply forked. Dorsal elevated in 

 front ; radii I. 6 ; C. 17 ; A. I. 5 ; Y. I. 5 ; P. I. 5 ; the spine flat, 

 reaching the basal fourth of the ventrals, with short spines out- 

 side which become teeth at the end; within smooth. Scapular 

 arch rather narrow below, followed by thi'ee series of shields, of 

 which the lateral are long and narrow. These gradually diverge 

 and admit three series of small scales, which again diminish and 

 terminate in an obtuse point between the ventral fins. This leaves 

 with the ends of the lateral shields a Y-shaped naked space, at 

 the end of which is situated the vent. These are covered with 

 numerous short bristles, like the scales of the dorsal region. The 

 head, esj^ecially the muzzle, and more particularly the sides of 

 the latter, are covered with many short, closely set, spiny bristles, 

 which give the whole fish a hoary appearance when dry. Spines 

 of fins also hirsute. Teeth bristle-like, those of the mandibular 

 rami opposed to each other. 



Yellowish-brown above, browner on the head, darkest on the 

 lores. Sides and below bright yellow, a weak dark shade on 

 lateral line, and large black spot at base of caudal. Fins un- 

 spotted. Total length .04 m. ; length to anal fin .02 ; width of 

 head behind .001. 



Tributaries of the Ambyiacu. 



LIPOSARCUS VARITJS, Cope, sp. nov. 



Radii D. II. 13, I. ; C. I. 14, I ; A. 5 ; Y. I. 5 ; P. I. 6. Dorsal 

 longer than high, basis nearly equal length in front of it. Pec- 

 toral spine to middle of ventral ; superior caudal ray shorter 



[February 13, 



