332 MEMOIRS OF THE CARNEGIE MUSEUM 



sometimes lacking. Second suborbital leaving a narrow naked area below. Six small, tricuspid, 

 and conical teeth in the maxillary. D. 11; A. 23 to 27; scales 5-32 to 34^3 to 4.5. . . . unilineatus. 

 aa. Dorsal without well-defined black markings (see also clegans). 



b. No humeral or caudal spot. Depth 3.33 to 3.75. A wide lateral streak from the middle of the caudal 

 to the head and another narrower streak from above the anterior anal rays to the mandible, with- 

 out black chromatophores; the sides and back everywhere else dusky. Anal lobe and distal 

 half of dorsal lobe dusky. Second suborbital about one-half as wide as the eye, without naked 

 margins. Maxillary with two to four, three- to five-pointed teeth. D. 11; A. 20 to 22; scales 



5-31 to 34-3 to 3.5 erythrozonus. 



bb. No humeral spot, caudal spot not as wide as the caudal peduncle, continued forward on the latter, 

 faintly continuous with the lateral stripe, and continued backward only on the middle rays. No 

 silvery area on the caudal peduncle. Second suborbital in contact with the preopercle. Head 

 4. Maxillary with two to four conical or tricuspid teeth. D. 11; A. 22-24; scales 5-32 to 34-2 



to 3.5 rodwayi. 



bbb. Humeral and caudal spots both developed. Dorsal equidistant from base of middle caudal rays and 

 tip of snout, or nearer the caudal. 

 c. Origin of the dorsal equidistant from front of eye and caudal. Origin of the anal on the vertical 

 from the last dorsal ray. Second suborbital leaving very narrow naked margins below and 

 behind. Humeral spot distinct, vertically elongate, surrounded by a bright area, often 

 with a second elongated spot behind the bright area. An iridescent spot on the upper half 

 of the caudal peduncle. Caudal spot often continued along the edge of each caudal lobe. 

 Maxillary with two or three conical or tricuspid teeth. Depth 2.5; D. 11; A. 22 to 26; 



scales 5-30 to 33-3 to 3.5 , ocellifer. 



cc. Origin of dorsal slightly nearer middle caudal rays than to tip of snout. Origin of anal on the vertical 

 from the first to the third scale behind the dorsal. Caudal spot wider than long, not continued 

 backward on the caudal peduncle. Humeral spot small. Maxillary with two four- or 

 five-pointed teeth. Second suborbital leaving narrow naked margins below and behind. 



D. 11; A. 1.5-17; scales .5-30-3 iota. 



bbbb. Humeral spot present; no caudal spot. (Humeral spot sometimes faint or lacking.) 

 (I. Anal rays 19-26. 



e. Compressed. Depth 3.75. Humeral spot faint or diffuse, roundish. Second suborbital 

 leaving narrow naked margins behind and below. Mouth moderately large. Maxillary 

 equal to eye. First seven anal rays dusky. D. 11; A. 19-22; scales 5-30 to 33-3. 



Caudal not deeply scaled, three to five scales on each lobe orthus. 



ee. Subcylindrical; eye a little longer than broad, 2.25 in the head; snout comparatively long, 

 3.25 in the head. Maxillary nearly straight, with three to six tricuspid or conical teeth. 



Humeral spot small and intense. D. 1 1 ; A. 17-20; scales 5-30 to 34-3 cylindricus. 



dd. Anal rays 12 to 14. Depth 3.2 to 3.5. Humeral spot diffuse. A wide silvery lateral stripe. Each 

 dorsal scale marked with an intense dark spot. Second suborbital leaving considerable 

 naked margins behind and below. Maxillary with two or three six- to seven-pointed teeth. 

 D. 11; A. 12-14; scales 5-30 to 32-3 analis. 



189. Hemigrammus unilineatus Gill. (Plate XLVIII, fig. 1.) 

 Poecilurichthys hemigrammus unilineatus Gill, Ann. Lye. Nat. Hist. N. Y., VI, 

 1858, 60 (Trinidad).— Gunther, Catalogue, V, 1864, 317. 



