FISHES OF THE FAMILY LOBICAEIID.E. 229 



distance from the caudal. A. I 4. Pectoral spine extending to the anterior third or 

 middle of ventral. Caudal emarginate, the outer rays produced. Caudal peduncle 

 3-3-j times as long as deep. Dark spots or vermiculations on the sides of the body ; 

 in the young, fins with dark cross-bars, in the adult with large dark spots. 



Total length 390 mm. 



A. — Head with dark vermiculations and spots on a light background, those of the 

 supraoccipital and interorbital regions with a more or less regular radiating arrangement. 

 Abdomen with large dark spots on a light ground-colour. 



Seven specimens (including the types of the species and of II. pzrdalis) : R. Amazon ; 

 Guiana. 



B. A. multiradiatus var. altemans, var. nov. — Head and abdomen with light spots 

 or vermiculations on a dark background. 



Three specimens : Paraguay and Southern Bolivia. 



7. f Ancistrus punctatus. 



Ancistrus duodecimalis (non Cuv. & Val.) Kner, Denksclir. Ak. Wien, vii. 1854, p. 281. 

 Pteryuoplichthys punctatus Giintu. Cat. Fish. v. p. 251 (1864) ; Eigenm. & Eigenm. Proc. Cal. Ac. 



(2) ii. 1889, p. 45 ; Occ. Pap. Cal. Ac. i. 1890, p. 431. 

 Chatostomus punctatus Steind. Denksclir. Ak. Wien, xliii. 1881, p. 115. 



This species is stated to resemble A. gibbiceps in form. In the number of scutes 

 and fin-rays, in the strongly carinate scutes, the low occipital crest, and the size of the 

 eye it is similar to A. multiradiatus, from which it appears to differ notably in the 

 narrower interorbital width (2f- 2f times in the length of head), the interoperculum 

 armed with a few spines, about 2 of which are moderately elongate in the adult, and 

 the pectoral spine extending only a little beyond the base of ventral. Head, body, 

 and fins with rather small round blackish spots. 



Venezuela ; Upper and Middle Amazon. 



8. Ancistrus medians. 



Ancistrus medians Kner, Denksclir. Ak. ATien, vii. 1854, pp. 256 and 281. 



Chcetostomus medians Gunth. Cat. Fish. v. p. 242 (1864). 



Hemiancistrus medians Eigenm. & Eigenm. Proc. Cal. Ac. (2) ii. 1889, p. 43. 



Depth of body 4-g- times in the total length, length of head 2f times. Plead as 

 long as broad and If times as long as deep. Diameter of eye 4—4-^ times in the length 

 of head, interorbital width 2f— 3 times, length of snout If— 1^ times. Length of 

 mandibular ramus If times in the interorbital width. Snout broad and rounded ; 

 supraorbital margins raised ; supraoccipital with median elevation ; temporal plates 

 carinate or not ; operculum reduced ; interoperculum armed with 30 or more rather 

 slender spines with curved tips, the longest equal to 1^ times the diameter of eye. 

 Scutes strongly spinulose, mostly carinate, 24 in a longitudinal series, 6-7 between 



