THE AMERICAN TETRAGONOPTERINAE. 201 
from the second scale in front of the dorsal. Ventrals reaching nearly or quite 
to the anal; pectorals reaching slightly beyond the base of the ventral. 
Caudal spot conspicuous, not continued on the middle caudal rays. Humeral 
spot obscure and vertically elongated. Lateral band indistinct. Highly iri- 
descent. Fins all dusky. 
I hesitate to unite H. proteus from Colombia with H. inconstans from 
Para. 
The following is the original description of H. proteus. The description 
above is drawn from two of the types of H. inconstans. 
Head 4; depth 2.25-2.66; D.11; A. 22, 23, 24, 23 28 the denominator in- 
dicating the number of individuals having the number of rays in the numer- 
ator. Scales 6 or 7 — #4, 33, %', 32, — 44 to 54; eye 2.6—-2.75, equals interorbital ; 
depth of caudal peduncle equal to its length. 
Compressed, oval; dorsal and ventral profiles nearly equally curved, 
only a slight depression in the profile over the eyes; preventral area narrow, 
rounded, without a distinct median series of scales; or with a regular series 
of about eleven scales; postventral area rounded, with three or four scales; 
predorsal area keeled, with a distinct median series of nine or ten scales; occi- 
pital process about 5 in the length from its base to the dorsal, bordered by three 
cr four pairs of scales; skull smooth, convex; parietal fontanel without the 
groove about one and a half times as long as the frontal fontanel. Second 
suborbital leaving a naked area one fifth to one half of its own width around its 
entire distal margin; maxillary-premaxillary border angulated, equal to a full 
diameter of the eye; the mouth terminal, the longitudinal extent of the pre- 
maxillary very short. Three or four teeth in the outer row of the premaxillary, 
five in the inner, the two rows parallel; a broad tipped, multipointed tooth on 
the maxillary; five rather small, 5-pointed graduate teeth in the mandible in 
front, none on the sides. 
Gill-rakers 7 + 12. 
Origin of dorsal about equidistant from snout and base of upper caudal 
lobe, its highest (second and third) rays about twice as high as the antepenulti- 
mate, the fin pointed, the highest ray a little longer than head; caudal lobes 
about 3 in the length; origin of anal behind the vertical from the last dorsal 
ray; anal emarginate, its base about 3.5 in the length; ventral usually not reach- 
ing anal, its origin equidistant from snout with the second or third scale in front 
of the dorsal, pectorals sometimes falling a little short of or extending a little 
beyond the origin of the ventrals. 
