214 ME. C. TATE REGAN OX THE 



a naked area behind the mouth and one at the base of each ventral. D. I 7, the first 

 ray as long as the head, and reaching the adipose fin when laid back, the last less 

 tban half as long ; length of base of dorsal equal to its distance from the posterior 

 part of the spine of the adipose fin. A. I 4. Pectoral spine extending nearly to 

 middle of ventral. Caudal emarginate. Caudal peduncle 2^ times as long as deep. 

 Uniformly olivaceous, the fins dusky. 



Total length 240 mm. 



One specimen from Paraguay. 



This species is very closely allied to P. latirostris, differing in the shorter and 

 deeper body, the longer barbel, the first dorsal ray reaching the spine of the adipose 

 fin when laid back, and the longer pectoral. 



15. Plecostomus maceops. 



Plecostomus inacrojis Eigeum. & Eigenm. Proc. Cal. Ac. (2) i. 1888, p. 170, and Occ. Pap. Cal. 

 Ac. i. 1890, p. 410. 



Depth of body 4f times in the total length, length of head 3^ times. Head as 

 broad as long, its depth If times in its length, diameter of eye 5f times, interorbital 

 width 2f times, length of snout If times. Length of mandibular ramus twice in the 

 interorbital width. Barbel a little shorter than the diameter of eye. Snout broad, 

 rounded; supraorbital edges raised; supraoccipital convex, elevated posteriorly, but 

 without distinct median ridge ; temporal plate not carinate. Scutes spinulose, not 

 carinate, 26 in a longitudinal series, 7 between dorsal and adipose fin, 14 between 

 anal and caudal. Supraoccipital entirely bordered posteriorly by a single scute. 

 Lower surface of head and abdomen covered with small granular scales, except for 

 naked areas behind the mouth and at the base of each ventral. D. I 7, the first ray 

 as long as the head, not reaching the adipose fin when laid back, the last f as long. 

 Length of base of dorsal equal to its distance from tip of spine of adipose fin. A. I 4. 

 Pectoral spine extending to anterior \ of ventral. Caudal emarginate. Caudal 

 peduncle 3J times as long as deep. Uniformly olivaceous. 



Total length 250 mm. 



One specimen (type of the species) from the Rio das Velhas, Eastern Brazil. 



16. Plecostomus garmani, sp. n. (Plate X. fig. 1.) 



Plecostomus lima (non Liitk.) Eigenm. & Eigenm. Occ. Pap. Cal. Ac. i. 1890, p. 409. 



Depth of body 6 times in the total length, length of head 3J times. Depth of head 

 ]f times in its length, breadth of head If times, length of snout 1| times, diameter of 

 eye 6J times, interorbital width 3J times. Length of mandibular ramus 1-f times in 

 the interorbital width. Barbel a little shorter than diameter of eye. Snout broad, 

 rounded ; supraorbital edges not raised ; supraoccipital slightly convex, without 



