eigenmann: the FRESHWATER FISHES OF BRITISH GUIANA 361 



One hundred and two specimens, 37-142 mm. ( reorgetown trenches. (C. M. 

 Cat. No. 1356a-z; I. U. Cat. No. 11848.) 



One hundred and twenty-two specimens. 51-126 mm. Botanic Garden. (C. 

 M. Cat. No. 1357a-.- I. U. Cat. No. 11849.) 



Seven specimens, 74-85 mm. Lama Stop-Off. (C. M. Cat. No. 1358a-6; I. 

 U. Cat, No. 11850.) 



One specimen, 79 mm. Maduni Creek. (C. M. Cat. No. 1359a.) 



Two specimens, 83-84 mm. Mora Passage. (C. M. Cat, No. 1360a; I. U. 

 Cat, No. 11851.) 



Head 3.5-4.3; depth 2-2.6; D. 11; A. 28-36, most frequently 32; scales 7-37 

 to 41-6; eye about 3 in the head; interorbital 2.3-2.4. 



Elliptical; predorsal area narrowly rounded, with a few median scales near 

 the dorsal. Occipital process one-third to one-fourth in the distance between its 

 base and the dorsal; second suborbital leaving a narrow naked area. 



Anal slightly emarginate in the young, straight in the adult, 



A well-defined, horizontally ovate, black humeral spot over the third to the 

 sixth, or second to the fifth scale of the lateral line; a spot on the caudal peduncle, 

 fading out forward and continued behind to the tip of the middle caudal rays. 



219. Poecilurichthys potaroensis (Eigenmann). (Plate LII, fig. 5.) 

 Astyanax potaroensis Eigenmann, Ann. Carnegie Mus., VI, 1909, 22; Repts. Prince- 

 ton Univ. Exp. Patagonia, III, 1910, 433. 



Type, 58 mm. Amatuk. (Carnegie Museum Catalog of Fishes No. 1037.) 

 Cotypes, twelve specimens, 51-64 mm. Amatuk. (0. M. Cat, No. 1038a-c; 

 I. U. Cat, No. 11733.) 



Cotype, one specimen, about 59 mm. Kangaruma. (C. M. Cat, No. 1039.) 

 Cotype, one specimen, 45 mm. Tukeit. (C. M. Cat. No. 1040.) 

 Cotypes, two specimens, 47-49 mm. Erukin. (C. M. Cat, No. 1041; I. U. 

 Cat. No. 11734.) 



Evidently allied to P. bimaculatus and P. orthodus. It is readily distinguished 

 from the former by the emarginate anal, the broad caudal band, and the absence 

 of any stripe on the caudal peduncle. In the coloration of the sides it approaches 

 P. abramoides, the humeral spot being less defined, the black lateral line being 

 absent. Its anal is distinctly shorter than that of orthodus. 



Head 3.5; depth 2.6-3; D. 11; A. 27 or 28, rarely 29; scales 8 (rarely 9)-37 to 

 38 v --6 or 7; eye 2.75; interorbital 3. 



52 Tn ten individuals five have 37, three have 38, one has 39, and one 41 scales. 



