[31] REVIEW OF THE SCILENIDZ. 373 
26. ANCYLODON ANCYLODON. 
Lonchurus ancylodon Bloch & Schneider, Syst. Ichth., 102, plate 25, 1801 (Surinam). 
Aneylodon jaculidens Cuv. & Val., Hist. Nat. Poiss.,v, 81,1830 (Cayenne). Giinther, 
Cat. Fish. Brit. Mus., ii, 311, 1860 (Surinam; West Indies). Jordan & Gil- 
bert, Bull. U.S. Nat. Mus., 1882, 111 (Panama). 
Ancylodon atricauda Giinther, Shore Fishes of the Challenger Exp., 1880, 12 (Mouth 
of Rio de la Plata). 
Habitat.—Both coasts of tropical America; Surinam; Panama. 
We have not been able to compare any specimens of this species in 
good condition, from Surinam, with specimens from Panama. The 
original types in the museum at Paris are in poor condition, but we did 
not see, when examining them, any characters by which we could sep- 
arate them from the specimens collected by Professor Gilbert at Panama. 
Our description is taken chiefly from a specimen in the museum at 
Cambridge from Rio Grande do Sul. Others from Guiana, Montevideo, 
and Rio Janeiro are in the same collection. 
The specimen described by Dr. Giinther as Ancylodon, atricauda dif- 
fers from our account only in having the head 3 in length and 31 rays 
in the soft dorsal. It is probably identical with A. ancylodon. 
Genus V.—NEBRIS. 
Nebris Cuvier & Valenciennes, Hist. Nat. Poiss., v, 149, 1830 (microps). 
TypE: Nebris microps Cuv. & Val. 
This genus is one of the most peculiar in the family. The cavernous 
structure of the head reaches in this genus its extreme of development, 
the head being more spongy to the touch than in Stelliferus, Collichthys, 
or Pachypops. But one species is known. 
We retain the name Nebris, notwithstanding the prior Nebria, as we 
regard the two names as sufficiently distinct. The number of vertebra 
in Nebris is 10+ 14. The genus, therefore, belongs to the Scienine and 
not to the Otolithina. 
ANALYSIS OF SPECIES OF NEBRIS. 
a. Body plump, anteriorly tapering to the slender caudal peduncle; profile straight 
head broad, heavy, extremely spongy above, eye minute, 94 in head, 24 in snout, 
4 in interorbital area; 14 in width of maxillary, which is very broad; mouth very 
large, oblique; lower jaw projecting, premaxillary anteriorly on a level with the 
middle of the eye; maxillary extending to below posterior margin of orbit, 24 in 
head ; teeth all minute, those of the lower jaw in a single series; those in upper 
jaw in a band which widens backwards; tongue large and thick; head entirely 
scaly ; margin of the preopercle indistinct, with a very wide membranous edge, 
which is nearly covered with scales; gill-rakers long and slender, 5 + 15; scales 
small, cycloid; lateral line little arched; the bases, at least of all the soft fins, 
densely covered with small scales; dorsal spines feeble, shorter than the dorsal 
rays; caudal lanceolate; pectorals 1} in head; ventrals 13; color silvery, darker 
above; pectorals dusky on their inner margin; head 3 in length; depth 44. D. 
VITI-I, 31; A.II-13. Scales 18-50 (pores)-18 1.1.2... .220 -seesacees MICROPS, 27. 
