236 MEMOIRS OF THE CARNEGIE MUSEUM 



103. Xenocara gymnorhynchus (Kner). 

 ? Hypostomus nudiceps Muller and Troschel, in Schomburgk, Reisen, III, 



1848, 631 (Takutu). 24 

 ? Chatostomus nudiceps Gunther, Catalogue, V, 1864, 249 (copied). — Eigenmann 



and Eigenmann, Proc. Cal. Acad. Sci., (2), II, 1889, 46; Occasional Papers 



Cal. Acad. Sci., I, 1890, 443; Proc. U. S. Nat, Mus., XIV, 1891, 43. 

 ? Ancistrus gymnorhynchus Kner, Denkschr. Akad. Wiss. Wien, VII, 1854, 275 



(Puerto Cabello). 

 Cha'tostomus gymnorhynchus Gunther, Catalogue, V, 1864, 249 (Puerto Cabello). 



— Lutken, Vid. Med. Naturhist. For. Kjobenhavn, 1874, 204. — Eigenmann 



and Eigenmann, Proc. Cal. Acad. Sci., (2), II, 1889, 46; Occasional Papers 



Cal. Acad. Sci., I, 1890, 444; Proc. U. S. Nat. Mus., XIV, 1891, 43.— Regan, 



Trans. Zool. Soc. London, 1904, 254. 

 Xenocara gymnorhynchus Eigenmann, Repts. Princeton Univ. Exp. Patagonia, 



III, 1910, 410. 



One specimen, 58 mm. Gluck Island. (C. M. Cat. No. 1526.) 



Head 3; depth at tip of occipital 6.5; interorbital 3.6 in the head; eye 5 in the 

 head; width of head an orbital diameter less than its length; mandibular ramus 

 2 in interorbital. D. 1,7; A. 1,4. No tentacles on the snout; the naked area 

 narrow, one-sixth the distance from tip of snout to posterior margin of eye along 

 the median line. Six plates between the dorsals, ten behind the anal, twenty- 

 five along the sides. 



Last dorsal ray not quite reaching the adipose, base of dorsal nearly equal 

 to its distance from tip of spine of the adipose fin; dorsal spine equal to snout and 

 orbit. 



Caudal sinuate, distinctly oblique, but the lower lobe a little longer than the 

 upper, equal to the length of the head. 



Blackish, with yellowish white, faintly ocellated spots; pectoral and ventrals 

 with faint spots; dorsal and caudal narrowly margined with reddish. 



24 1 have been able to examine the type of nudiceps in the Berlin Museum, 10.5 mm., No. 3180, 

 Guiana. Schomburgk. 



Head 2+; depth at occipital process 6+; interorbital 2.4 in the head; eye 5.5 in the head; width of 

 the head an orbital diameter less than its length; mandibular ramus 3.4 in the interorbital; D. 1,7; A. 

 1,4; no tentacles about the snout; naked area at least one-third the distance from tip of snout to pos- 

 terior margin of the eye along the median line; five plates between the last dorsal ray and the spine of 

 the adipose, nine behind the anal, twenty-two along the sides. Pectoral reaching to the second fourth 

 of the ventral; ventral beyond the base of the last anal ray. In other distinguishable characters it is like 

 the specimen from Gluck Island. 



