224 MEMOIRS OF THE CARNEGIE MUSEUM 



Akad., II KL, X, 1865, 60.— Hensel, Archiv fur Naturg., XXXVI, 1870, 75 



(Rio Cadeo). — Steindachner, " Flussfische Siidamerika's," ii, 1881, 109. 

 Hypostomus robinii Gill, Ann. Lye. Nat. Hist. N. Y., VI, 1858, 46 (Trinidad). 

 Plecostomus brasiliensis Bleeker, " Silures de Suriname," 1864, 7 (Surinam). 

 Plecostomus seminudus Eigenmann and Eigenmann, Proc. Cal. Acad. Sci., (2), I, 



1888, 169 (Brazil); Occasional Papers Cal. Acad. Sci., I, 1890, 409. 

 Plecostomus boulengeri Eigenmann and Kennedy, Proc. Acad. Nat. Sci. Phila., 



1903, 502 (Paraguay). 



One specimen, 370 mm. Georgetown. (C. M. Cat. No. 1541.) 



One specimen, 148 mm. Kumaka. (C. M. Cat. No. 1542.) 



Three specimens, 164-210 mm. Wismar. (C. M. Cat. No. 1543a; I. U. Cat. 

 No. 11962.) 



.Head 3; depth 5-5.75; D. 1,7; A. 1,4; scutes 26; eye 6; interorbital 2.66 in 

 the head; mandibular ramus 2.75 in the interorbital. 



Occipital with a blunt keel, bordered by a single plate behind; plates forward 

 of the adipose largely keeled. 



Dorsal spine equal to pectoral spine, about equal to the length of the head; 

 base of dorsal equal to its distance from the tip of the spine of the adipose. 



Reddish-brown, with olive spots, smallest on the head, absent on the belly; 

 dorsal with a series of spots along the anterior part of the rays, sometimes confluent 

 into bars, alternating with reddish bars. Caudal with alternating bars of olive 

 and rusty. 



91. Plecostomus hemiurus sp. nov. (Plate XXV, fig. 1.) 



Plecostomus hemiurus Eigenmann, Repts. Princeton Univ. Exp. Patagonia, III, 



1910, 407 (name only). 



Type, 201 mm. Amatuk. (Carnegie Museum Catalog of Fishes No. 1544.) 



Cotypes, four specimens, 158-180 mm. Amatuk. (C. M. Cat. No. 1545a; 

 I. U. Cat. No. 11963.) 



Seven specimens, 27-113 mm. Waratuk. (C. M. Cat. No. 1546a-e; I. U. 

 Cat. No. 11964.) 



Four specimens, 68-150 mm. Crab Falls. (C. M. Cat. No. 1547a; I. U. 

 Cat. No. 11965.) 



Two specimens, 70-87 mm. Rockstone. (C. M. Cat. No. 1548; I. U. Cat. 

 No. 11966.) 



One specimen, 71 mm. Gluck Island. (C. M. Cat. No. 1549.) 



Two specimens, the larger 190 mm. Ireng? (C. M. Cat. No. 1550; I. U. 

 Cat. No. 11967.) 



