FISHES OF THE FAMILY LORICARIIDA. 249 
smaller eye (diameter 10 times in the length of head), 4 or 5 interopercular spines, 
and the pectoral spine not extending beyond the anterior 1 of the ventral. Yellowish 
brown, without spots; tips of the lobes of the caudal light. 
The type, from Puerto Cabello, Venezuela, is 205 mm. in total length. 
9. CH £ZTOSTOMUS GUAIRENSIS. 
Chetostomus guairensis Steind. Denkschr. Ak. Wien, xliii. 1881, p. 121, pl. iii. fig. 1. 
Depth of body about 53 times in the total length, length of head 3 times. Head 
as broad as long and nearly twice as long as deep. Diameter of eye 5-7 times in the 
length of head, interorbital width 3 times, length of snout 13-2 times. Interoperculum 
armed with 4-5 spines. 23 scutes in a longitudinal series, 6-7 between dorsal and 
adipose fin, 10-11 between anal and caudal. D.I 8, the first ray equal to 2 the 
length of head, the last 3 as long; length of base of dorsal equal to its distance from 
the posterior 4 of the spine of the adipose fin. A.15. Pectoral spine extending a 
little beyond base of ventral. Caudal slightly and obliquely emarginate. Caudal 
peduncle about 24 times as long as deep. Head with large light spots separated by a 
dark network ; body greyish, marbled with darker; fins, except the anal, with dark 
bars ; caudal with a narrow light edge. 
This species, founded on specimens up to 110 mm. in total length, from Caracas, 
Venezuela, may prove to be identical with the preceding. 
10, CHA&TOSTOMUS MARGINATUS, sp.n. (Plate XIII. fig. 1.) 
Depth of body 53-53 times in the total length, length of head 34-32 times. 
Head as broad as long and about 1? times as long as deep. Diameter of eye 7-9 
times in the length of head, interorbital width 5-54 times, length of snout 13-13 times. 
Length of mandibular ramus equal to or a little greater than the interorbital width. 
Interoperculum armed with 5 short spines. 24-25 scutes in a longitudinal series, 
7-8 between dorsal and adipose fin, 10-11 between anal and caudal. D. I 8, the first 
ray equal to § the length of head, the Jast 2 as long; length of base of dorsal equal to 
its distance from the adipose fin. A.1I5. Pectoral spine extending to anterior ¥ of 
ventral. Caudal slightly and obliquely emarginate. Caudal peduncle 24-3 times as 
- long as deep. Olivaceous, with little yellowish dots on the head ; dorsal rays and the 
membrane on each side blackish, leaving a light streak in the middle of each inter- 
radial membrane; caudal with a narrow light edge. In the young a series of light 
spots on each dorsal ray. 
Total length 190 mm. 
Three specimens, from Salidero, N.W. Ecuador, collected by Mr. Rosenberg, had 
been referred by Boulenger to C. microps in his account of the Rosenberg collection. 
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