THE AMERICAN TETRAGONOPTERINAE. 217 



Head 3.5 to 3.8; depth 2.75 to 3.25; D. 11; A. 26-31; scales 6-33 to 35-4; 

 eye 2.25 in head, snout 2 m the eye; interorbital less than the eye, about 2.5 in 

 head. 



Compressed. Depth of head at the base of the occipital process 1.33 to 1.5 

 in the greatest depth. Preventral region rounded, without regular complete 

 series of median scales. Predorsal region rounded, with complete series of 9 to 

 11 median scales. 



Occipital process 5 in the distance from its base to the dorsal, bordered 

 by 5 scales. Interorbital very slightly convex. Frontal fontanel large, tri- 

 angular, only slightly narrower than parietal, as long as the parietal without 

 the occipital groove. Second suborbital leaving naked margins behind and 

 below. Mouth moderately large; snout short. Maxillary not so long as the 

 eye. Mandible equal to the eye. Premaxillary with two or three, rarely 

 four, small 5- to 7-pointed teeth in the outer row, and five large 7- to 9-pointed 

 teeth in the inner row. Maxillary with one to three broad 7-pointed teeth. 

 Dentary with five or six large 7- to 9-pointed teeth followed by two or three 

 very small, but multicuspid teeth on the side. 



Gill-rakers about 5 -|- 11. 



Base of the caudal sometimes a very little scaled, the broad terminal scale 

 often wanting. Anal sheath short, composed of four scales covering the bases 

 of the first 6 rays. Pores on 7 to 11 scales. 



Origin of the dorsal a third the length of the eye nearer the base of the 

 caudal than the snout; penultimate rays 4 in the longest which is 2.5 to 2.67 

 in the length. Origin of anal on the vertical from the last dorsal ray; longest 

 ray 1.66 in the base which is 1.2 times the head. Ventrals on the vertical from 

 the first or second scale in front of the dorsal. Ventrals just reaching the anal. 

 Pectoral never reaching beyond the second scale in front of the ventrals. 



Humeral spot round, very intense, surrounded by a fight ring; the center 

 of humeral spot equidistant from posterior margin of the eye and the dorsal; 

 very frequently a less intense dai'k bar extending obliquely downwards and 

 forwards, and another shorter one extending obliquely upwards and forwards. 

 A faint secondary hiuneral spot the width of two scales behind the first. Lateral 

 stripe sharp and very narrow, not reaching the caudal. No caudal spot. Dorsal 

 scales outlined with dusky. Sides silvery iridescent. 



Caudal peduncle to in front of adipose, the adipose and caudal except the 

 lobes richest cherry-red. Caudal lobes, anal, and dorsal canary-yellow. 



A specimen from Lama Stop-Off 24 mm. has more than ordinary number 

 of scales on the caudal and only 19 anal rays. 



