172 Annals of the Carnegie Museum. 



and third or fourth, are largest; all the teeth, except the last ones on 

 the dentary, tricuspid, the cusps all sharp, the middle one longest, 

 ('■ill-rakers very slender, 4 + 12, those on the upper arch very much 

 shorter than those near the angle of the lower arch, which are aboul 

 one-fourth of the eye in length. Dorsal rounded, its origin about 

 equidistant from eye and middle caudal rays, its highest ray about 

 4.5 in the length; adipose dorsal well developed; caudal deeply 

 forked, the lobes 3.5 in the length; anal long, its origin a little nearer 

 the snout than the base of the middle caudal rays; ventrals small, just 

 reaching the anal; pectorals large, falcate, sometimes reaching to the 

 anal. Scales regularly arranged on the caudal peduncle, less regularly 

 arranged on the sides above the lateral line; below the lateral line 

 with main- interpolated rows, so that the series run obliquely down- 

 ward; anal with a sheath of two series of scales along its base in 

 front; caudal naked, sometimes a slight swelling on the bases of the 

 rays just above and just below the middle; radial striae short or none. 

 Cheeks and opercles highly iridescent; a well-developed humeral bar; 

 no caudal spot, the middle rays dusky. 



<s. Creagrutus beni 6 sp. now 



Plate VI, fig. 2. 



Type. — One specimen, 53 mm. C. M. No. 3216. Villa Bella on Rio Beni, 

 Oct. 5, 1909. 



Head 4.33; depth 3.5; D. 10; A. 13; scales 4-40-3. Eye 3 in the 

 head; interorbital equals the eye. Subcylindrical; predorsal area 

 rounded, with a median series of eight scales; ventral area rounded, 

 without a distincjt median series of scales. Occipital process very 

 short, bordered by one and one-half scales on each side; cheeks 

 narrower than the eye, second suborbital in contact with the pre- 

 opercle below, but not behind and in front; snout and maxillary 

 about equal to the eye; lower jaw distinctly shorter. Maxillary with 

 three graduated teeth, premaxillary with an outer row of five tri- 

 angular or tricuspid teeth, the second, third, and fourth more and 

 more withdrawn, so that the fourth is between the fifth of the outer 

 series and the second of the inner series. Gill-rakers slender, 9 + 12. 

 Anal sheath very small; base of each caudal lobe with a few scales. 

 Origin of dorsal equidistant from tip of adipose and tip of snout; 



6 A poorly preserved specimen from below the Cachoeira de Velha de Rio Nova, 

 near Fiabana, may belong here. 



