FISHES OF THE FAMILY LORICARIIDA. 205 
8. Supraorbital edges not raised ; length of mandibular 
ramus 14-21 in the interorbital width. 
26 scutes in a longitudinal series; diameter of eye 
6} times in the length of head (in a specimen of 
260 mm.) ! . : - + « . « . 16. P. garmani Regn. 
26 scutes ina A sae series ; Biametee of eye 7 times 
in the length of head (in a specimen of 130 mm.) ; 
caudal peduncle 22 times as long as deep. . . . 18. P. une Stdr. 
26 scutes in a longitudinal series; diameter of eye 8 times 
in the length of head (in a specimen of 250 mm.) ; 
caudal peduncle 3 times as long as deep ; abdomen, 
in the adult, in great part covered with granular 
Ses Ge cline LO el-azoecren enc: ©. bln 
27 scutes in Pio dethadinal series ; Ledeen in the dine 
almost entirely naked . . . . - « . ~ 20. P. luetkent Stdr. 
y. Supraorbital edges slightly raised; lent of enaabilan 
ramus 13 times in the interorbital width . . . . 21. P. auroguttatus Kner. 
II. Adipose fin small or absent ; operculum and interoperculum with well-developed 
marginal bristles. (PoGonoroma, subgen. n.) 
wo 
© 
A. Adipose fin present . P. wertheimeri Stdr. 
Bb. No adipose fin. 
Length of snout 24 times in that of the head, which is 33 
times in the total length. . . . . ‘ . . 23. P. pellegrini Ren. 
Length of snout twice in that of the head, aifon is 3. 34 
times in the totallength. . . . . . . . . . 24 P. genibarbis C. & V. 
III. Adipose fin absent; operculum and interoperculum not margined with bristles. 
(RHINELEPIS Spix.) 
Interorbital width 24-22 times in the length of head; opercular plate 
rather large ; abdomen almost entirely naked. . . . . 25. P. parahybe Stdr. 
Interorbital width 12 times in the length of head; ppexeniat state 
very large ; abdomen entirely covered with granular scales. . . 26. P. asper Spix. 
1. PLECOSTOMUS GUACARI. 
Loricaria plecostomus Linn. S. N. i. p. 508 (1766) ; Bloch, Ausl. Fische, viii. pl. 374 (1794) ; 
Bl. Schn. p. 124 (1801). 
Hypostomus guacari Lacép. Poiss. v. p. 145 (1803). 
Loricaria flava Shaw, Zool. v. p. 38, pl. ci. (1805). 
Hypostomus plecostomus Schomburgk, Fish. Guiana, i. p. 139 (1841) ; Kner, Denkschr. Ak. Wien, 
vii. 1853, p. 263. 
Plecostomus bicirrhosus Gronow, Cat. p. 158 (1854) ; Giinth. Cat. Fish. v. p. 231 (1864) (part.) ; 
Kner & Steind. Abhandl. bayr. Ak. x. 1865, p. 60; Hensel, Arch. Nat. 1870, p. 75; Steind. 
Denkschr. Ak. Wien, xlii. 1881, p. 109. 
Hypostomus robinit Gill, Aun. Lye. N. York, vi. 1858, p. 46. 
Plecostomus brasiliensis Bleek. Nat. Verh. Holl. Maats, xx. 1864, Silures de Surinamie, p. 7. 
