THE AMERICAN TETRAGONOPTERINAE. 215 



of each anal ray. The first 11 to 13 of these interpolated scales larger and ex- 

 tending onto the base of the raj^s so as to form a short anal sheath. Lateral 

 Une with pores on the first 6 to 9 scales. 



Origin of the dorsal equidistant from the snout and caudal; penultimate 

 ray about one third of the longest which is 3.33-3.67 in the length. Caudal 

 a Uttle shorter than the head. Origin of the anal on the vertical from the 

 eighth dorsal ray. Anal of male somewhat rounded, the last ray one half 

 the longest which is almost twice the length of the eye. Anal armature devel- 

 oped as a series of small recurved hooks on each of the first fifteen to twenty rays. 

 Anal of the female emarginate, the longest ray 1.67 in the anal's base; the last 

 rays much shorter than in the males of equal size. Ventrals on the vertical 

 from the first or second scale in front of the dorsal, barely reaching the anal in 

 females but prolonged to the base of the seventh to tenth anal rays in males. 

 Pectorals just reaching the ventrals. 



A vertically elongate humeral spot, followed by a bright bar, and a second 

 dusky bar extending almost entirely across the sides. Seven to twelve black 

 V-shaped Unes, the angle toward the head, along the very faint silvery lateral 

 stripe. No caudal spot. Fins all somewhat dusky except along the outside 

 of the ventrals of the males and sometimes at the bases of the caudal and anal 

 in females. Scales of the back and upper half of the sides outhned with dusky. 

 The region over the anal with many large pale chromatophores. The very young 

 specimens, 16-24 mm., from Cacequy had all the markings very poorly devel- 

 oped, the chromatophores being more evenly distributed. 



32. Hyphessobrycon catableptus (Durbin). 



Demalocheir catablepla Dukbin, Ann. Carnegie mus., 1909, 6, p. .55; Eigenmann, Mem. Carnegie mus., 

 1912, 5, p. 343. 



Habitat. — Guiana. 



One specimen 1198 C. Type. 18 mm. Tumatumari, above the Falls. 



Eigenmann. 



Head 3.5; depth 3.8; D. 11; A. 20; scales 5-33-3; eye 2.5 in the head; 

 interorbital very slightly greater than the eye 2.2 in head. 



Compressed. Depth of head at the base of the occipital process very nearly 

 equal to the greatest depth. Preventral region rounded, without complete 

 series of median scales. Predorsal region rounded. 



Occipital process short. Interorbital flat. Frontal fontanel triangular, 



