306 ME. C. TATE BEGAN ON THE 



Subfamily IV. Neoplecostomin^. 



Vertebrae below the dorsal fin with bifid neural spines ; those above the anal fin with 

 bifid hcemal spines ; lower and fourth upper pharyngeals toothed ; teeth in the jaws in 

 a single series; no pseudobranchise ; upper part of the body enclosed in bony scutes, 

 which form 5 series anteriorly on each side of the nearly cylindrical caudal peduncle, 

 3 posteriorly ; lower part of clavicle and coracoid not exposed ; anterior rudimentary 

 ray of ventral represented by a small internal plate, elongate-oval in form. 



This subfamily is here established for a single genus and species, which, although 

 it has been referred to Plecostomus, proves to be far more nearly allied to Loricaria 

 than to that genus. It is also of considerable interest as being the nearest repre- 

 sentative among the forms with the body enclosed in bony scutes to the naked 

 Argiinae. 



15. Neoplecostomus. 



Neoplecostomus Eigenm. & Eigenm. Proc. Cal. Ac. (2) i. 1888;, p. 170. 



Body moderately elongate ; eyes small ; teeth bifid. Abdomen with a large square 

 patch of small granular plates. Dorsal originating above or a little behind the 

 ventrals, with I 7 rays, anal with I 5-6, pectoral with I 6, ventral with I 5. Adipose 

 fin present. Caudal emarginate. Vertebra b + 8 + 18. Ribs slender. 



Neoplecostomus gkanosus. 



Hypostomus granosus Cuv. & Val. Hist. Nat. Poiss. xv. p. 502 (1840). 



Plecostomus granosus Gunth. Cat. Eisk. v. p. 237 (1864). 



Plecostomus microps Steind. Sitzb. Ak. Wien, lxxiv. 1876, pt. i. p. 688, pi. xiii. 



Neoplecostomus microps Eigenm. & Eigenm. Proc. Cal. Ac. (2) i. 1888, p. 170, and Occ. Pap. Cal. 



Ac. i. 1890, p. 395. 

 Neoplecostomus granosus Eigenm. & Eigenm. 1. c. et 1. c. 



Depth of body 6-1—7 times in the total length, length of head oj times. Breadth of 

 head 1^ times in its length, diameter of eye 10-13 times, interorbital width 3 times, 

 length of snout 1\- 1-f times. Length of mandibular ramus If— 2 times in the inter- 

 orbital width. Head depressed, nearly flat above; snout broad, rounded; barbel very 

 short or absent. Scutes spinulose, not carinate, 2S-30 in a longitudinal series. 

 Lower surface of head naked ; abdomen with a square patch of small granular plates. 

 D. I 7 ; length of base of dorsal about equal to its distance from the supraoccipital. 

 A. I 5-6. Pectoral spine extending to anterior j of ventral. Caudal emarginate. 

 Caudal peduncle 3f-4^ times as long as deep. Brownish, marbled with darker ; fins 

 with dark spots or cross-bars. 



Total length 102 mm. 



Several specimens (including the types of the species) : Cayenne ; Eastern Brazil. 



