348 MR. C. TATE REGAN ON THE 
6. CHTOSTOMUS DERMORHYNCHUS. 
Chetostomus dermorhynchus Bouleng. Proc. Zool. Soc. 1887, p. 277, pl. xxit. 
Depth of body 48-5 times in the total length, length of head 3-33 times. Head as 
broad as long and 14-13 times as long as deep. Diameter of eye 6-8 times in the 
length of head, interorbital width 3-3} times, length of snout 13-1§ times. Length 
of mandibular ramus equal to or a little greater than the interorbital width. Inter- 
operculum armed with 4 or 5 short spines. 24 scutes in a longitudinal series, 
6 between dorsal and adipose fin, 10 between anal and caudal. D. 1 8 (rarely I 9), 
5 the length of head, the last 3-3 as long; length of base 
of dorsal equal to its distance from posterior part of spine of adipose fin. A. 15 
(rarely I 4). Pectoral spine extending a little or considerably beyond the base of 
ventral. Caudal peduncle twice as long as deep. Olivaceous, some dark spots on 
the head, a few series of dark or light spots on the sides of tne body; dorsal with 
dark or light spots on the rays and a dark spot at the base of the first interradial 
membrane. 
the first ray equal to 
Total length 250 mm. 
Six specimens from K. Ecuador. 
7. PCuaTOSTOMUS FISCHERL. 
Chetostomus fischeri Steind. Denkschr. Ak. Wien, xli. 1879, p. 164, pl. iv. fig. 9. 
Depth of body 53-54 times in the total length, length of head 34-35 times. Head 
as broad as long and 13 times as long as deep. Diameter of eye 8-8} times in the 
length of head, interorbital width 3-3} times, length of snout 1}-1} times. Inter- 
operculum armed with 1—2 spines, 23-24 scutes in a longitudinal series, 6-7 between 
dorsal and adipose fin, 10-11 between anal and caudal. D. 13, the first ray equal to 
* the length of head, the last 3 as long ; length of base of dorsal equal to its distance 
from the posterior } of the spine of the adipose fin. A.1I5. Pectoral spine extending 
to middle of ventral. Caudal obliquely and slightly emarginate. Caudal peduncle 
about 24 times as long as deep. Little yellowish dots on the head and anterior 
part of body ; fins spotted or clouded with blackish. 
The types, from the Rio Mamoni, near Chepo, measure up to 275 mm, in total 
length. 
8. tCHATOSTOMUS STANNII. 
Chetostomus stannii Liitk. Vid. Medd. 1874, p. 209; Steind. Denkschr. Ak. Wien, xlii. 1881, 
p- 120, pl. v. fig. 4. 
Very closely allied to the preceding species, with which it agrees in the form and 
proportions of head and body and the number of scutes and fin-rays, but with a 
