164 THE AMERICAN CHARACIDAE. 
timate ray 2.5 in the longest, which is about 3.5-3.25 in the length. Origin of 
the anal on the vertical from the eighth or last dorsal rays. Anal emarginate, 
its longest ray 1.25 in the base. Ventrals on the vertical from the first scale in 
front of the dorsal. Ventrals reaching to the fifth anal ray. Pectorals often 
reaching a little beyond the base of the ventrals. 
Fins all hyaline; humeral spot small, dark and surrounded by a ring of 
light, an inconspicuous silvery lateral stripe, widest at the vertical from the adi- 
pose, not reaching the caudal spot and subtended by a faint, slaty gray line; 
caudal spot almost as wide as the caudal peduncle, terminating abruptly before 
and more gradually behind, not, however, extending to the tips of the middle 
caudal rays. Sometimes a little black near the tips of the first anal rays. 
Seales of back and upper part of the sides broadly outlined with dusky. Scales 
below the lateralstripe with pale bluish and greenish iridescence. 
20. HrMIGRAMMUS LUNATUS Durbin. 
Hemigrammus lunatus Dursix MS. E1rcenmann, Princeton univ. exped. Patagonia, 1910, 3, p. 436 
(Amazon); Exits, Ann. Carnegie mus., 1911, 8, p. 162 (Caceres; Jaurti; Rio Boa Vista). 
Haprrat.— Amazon Basin. 
Specimens examined. 
Number of 
Catalogue number specimens Size in mm. Locality Collector 
20964 Type 1 33 
20964 Paratypes 3 27-32 
20840 Paratype 1 32 Obidos 
3081 C. 5 24-45 Caceres Haseman 
2942 C, 4 46, 48 Jauru Haseman 
Head 3. to 3.2; depth 2.75; D.11; A. 23 to 26; scales 5-33 to 34-3.5; 
eye 2.25 in the head, interorbital not quite equal to the eye, 2.5 to 3 in the head. 
Very compressed; depth of head at the base of the occipital process about 
1.5 in the greatest depth. Preventral region rounded, with a complete median 
series of 10 or 11 scales. Predorsal region narrowly rounded, with a complete 
median series of 10 scales. 
Occipital process about 5 in the distance from its base to the dorsal, bor- 
dered by 3 seales. Interorbital slightly convex. Frontal fontanel triangular, 
very nearly as wide as the parietal, equal to the parietal without the occipital 
groove. Second suborbital moderately wide, leaving a very narrow naked 
margin behind but sometimes none below. Snout short, mouth large. Maxil- 
