218 MR. C. TATE REGAN ON THE 
ventral. Caudal obliquely emarginate. Caudal peduncle 3 times as long as deep. 
Olivaceous, some dark spots on the dorsal ; indistinct light spots on the upper part of 
the body. 
Total length 500 mm. 
Two specimens (including the type of H. asperatus): E. Brazil. 
22. PLECOSTOMUS WERTHEIMERI. 
Plecostomus wertheimeri Steind. Sitzb. Ak. Wien, lv. 1867, p. 701, pl. 1. 
Pseudancistrus wertheimeri Eigenm. & Eigenm. Proc. Cal. Ac. (2) ii. 1889, p. 45, and Occ. Pap. 
Cal. Ac. 1. 1890, p. 436. 
Depth of body 4} times in the total length, length of head 3% times. Head 
12 times as long as broad and 1} times as long as deep. Diameter of eye 6} times in 
the length of head, interorbital width 25, length of snout twice. Length of mandibular 
yamus 22 times in the interorbital width. Snout obtuse ;- upper surface of head 
nearly flat, without keels or ridges ; operculum and interoperculum with rather 
short marginal bristles. Scutes not carinate, 23 in a longitudinal series, 8 between 
dorsal and adipose fin, 11 between anal and caudal. Supraoccipital bordered 
posteriorly by a pair of scutes. A group of small granular plates behind the temporal 
plate. Lower surface of head and abdomen naked, except for a patch of small 
granular plates in front of each gill-opening, a strip between the pectorals, and a 
lateral series of well-developed plates on each side of the abdomen. D. I 7, the first 
ray as long as the head, the last 2 as long; length of base of dorsal slightly greater 
than its distance from adipose fin. Adipose fin small. A. I 5. Pectoral spine 
extending to base of ventral. Caudal weakly and obliquely emarginate. Caudal 
peduncle 24 times as long as deep. Brownish; some indistinct lighter spots on 
upper part of body; dorsal with a dark vertical stripe or series of spots on each 
interradial membrane. 
Total length 220 mm. 
One specimen: Santa Clara, S.E. Brazil. 
23. PLECOSTOMUS PELLEGRINI, Sp. 0. 
Depth of body 4 times in the total length, length of head 5} times. Head a little 
broader than long and 1} times as long as deep. Diameter of eye nearly 6 times in 
the length of head, interorbital width twice, length of snout 23 times. Length of 
mandibular ramus 33 times in the interorbital width. Snout short, broad, rounded ; 
supraorbital edges not raised ; supraoccipital with a low median ridge; operculum and 
interoperculum with short marginal bristles. 23 scutes in a longitudinal series, 
10 between anal and caudal, the anterior and upper scutes with strong but obtuse 
keels. Supraoccipital bordered posteriorly by a median scute and by one on each 
