238 MEMOIRS OF THE CARNEGIE MUSEUM 



1891, 43. — Eigenmann, Repts. Princeton Univ. Exp. Patagonia, III, 1910, 411. 

 XenocaratemmincLii Regan, Trans. Zool. Soc. London, XVII, 1904, 254 (Guiana). 



Two specimens, 74 and 56 mm. Packeoo Falls. (C. M. Cat. No. 1520a; 

 I. U. Cat. No. 11946.) 



Two specimens, 47 and 38 mm. Rupununi Pan. (C. M. Cat. No. 1521a; 

 I. U. Cat. No. 11947.) 



Two specimens, 43 and 52 mm. Chipoo Creek, a branch of the Ireng near 

 Karakara. (C. M. Cat. No. 1522; I. U. Cat. No. 11948.) 



Head 3 or a little less, depth at tip of occipital 5.5 in the length; width of head 

 about an orbital diameter less than its length; interorbital about 2.5 in the length 

 of the head; mandibular ramus 2.33-3 in the interorbital; D. 6; A. 1,4; eye 5.5 in 

 the head (in the largest specimen). About ten interopercular spines; naked part of 

 the snout (in the largest specimen) extending one-fourth the distance to posterior 

 margin of eye along the median line; three pairs of plates between the occiput and 

 the dorsal, five plates between the dorsals, ten between the last anal ray and 

 the caudal, and twenty-three along the sides. 



Head finely granular, granules of posterior part of occipital arranged in faint 

 radiating rows; plates of the sides with series of spines; last dorsal ray extending 

 to the spine of the adipose; length of base of dorsal equal to its distance from the 

 middle of the spine of the adipose dorsal; dorsal spine an orbital diameter or less 

 shorter than the head; lower caudal rays equal to length of head. Ventrals 

 rounded, reaching to middle of anal ; pectoral to third fifth of ventrals. 



General effect dark. Numerous light spots about as large as the pupil, 

 smaller below, the spots of the back sometimes confluent, in rows. Dorsal with 

 three to five wavy cross-bands; caudal spotted with dark, other fins with cross- 

 spots. Dorsal and caudal sometimes margined with light. 



The color of the specimens in the Leiden Museum is uniformly dark. The same 

 is true of the specimen in Berlin collected by Schomburgk in Guiana. As the latter 

 is in rather bad condition I am not prepared to say whether it belongs to the 

 present species or the next. 



105. Ancistrus cirrhosus (Cuvier and Valenciennes). 

 Hypostomus cirrhosus Cuvier and Valenciennes, Hist. Nat. Poiss., XV, 1840, 511 



(Rio Janeiro; Buenos Ayres) . — Valenciennes, in d'Orbigny, Voy. Am. Mer., 



V, ii, 1847, pi. 7, fig. 3. 

 Ancistrus cirrhosus Kner, Denkschr. Akad. Wiss. Wien, VII, 1854, 272 (Rio Gua- 



pore). — Eigenmann and Eigenmann, Proc. Cal. Acad. Sci., (2), II, 1889, 



