242 MR. C. TATE REGAN ON THE 
4, PANAQueE. 
Cochliodon (non Cochlodon D’Orbigny) Kner, Denkschr. Ak. Wien, vii. 1854, p. 265; Eigenm. & 
Eigenm. Proc. Cal. Ac. (2) ii. 1889, p. 44, and Occ. Pap. Cal. Ac. i. 1890, p. 424. 
Panague Eigenm. & Eigenm. 1. ec. and t. c. p. 425. 
This genus is distinguished from Ancistrus by the teeth, which are few in number 
and spoon-shaped. D.1I7. A.I 4. 
Magdalena, Orinoco, Amazon, and La Plata Systems. 
Key to the Species. 
I. Interoperculum not notably spinate. . . . . . . 1. P. cochliodon Kner. 
11. Interoperculum armed with some slender eeersbie = spines. 
A. Supraoccipital nearly flat . . - . . - . - . . . . 2 P. dentew Gthr. 
B. Supraoccipital arched, elevated. 
Diameter of eye 9 times in the length of head, interorbital width twice 
(in specimen of 180mm.) . .- ss 3. P. gibbosus Stdr. 
Diameter of eye 7} times in the length of healt interor bital width 14 times 
as 
(in specimen of 210 mm.) P. nigrolineatus Ptrs. 
1. PANAQUE COCHLIODON. 
Hypostomus cochliodon Kner, Denkschr. Ak. Wien, vii. 1854, p. 265, pl. ii. fig. 1. 
Plecostomus cochliodon Giinth. Cat. Fish. v. p. 238 (1864). 
Cochliodon cochliodon Figenm. & Eigenm. Proc. Cal. Ac. (2) ii. 1889, p. 44, and Oce. Pap. Cal. Ac. 
i. 1890, p. 425. 
Depth of body 4 times in the total length, length of head 3-3} times. Head 1§ 
times as long as broad and 12 times as long as deep. Diameter of eye 63-64 times in 
the length of head, interorbital width 14-2} times, length of snout 13-1} times. Both 
jaws with 8 or 9 teeth on each side. Snout narrowed anteriorly, supraorbital edges 
moderately raised ; supraoccipital with median ridge, ending posteriorly in a pointed 
process; temporal plates obscurely carinate ; interoperculum scarcely more spinate than 
the other plates of the head. Scutes spinulose, the anterior carinate, 27 in a longitudinal 
series, 8 between dorsal and adipose fin, 14-15 between anal and caudal. Supra- 
occipital entirely bordered posteriorly by a single scute. Lower surface of head and 
abdomen completely covered with small granular scales. D.1I7; length of base of 
dorsal equal to its distance from the middle of the spine of adipose fin. A. I 4. 
Pectoral one extending to anterior } of ventral. Caudal emarginate. Caudal 
peduncle 3} times as long as deep. Olivaceous, with some dark spots on head, body, 
and fins. 
Total length 200 mm. 
Two specimens: Paraguay; R. Jungada, Matto Grosso; Rio Cujaba. 
