Eigenmann: The Serrasalmin.i^- and Mylin^.. 251 



Head 3.3-3.6; de]ith 2.3-2.44 in the length to the end of the lateral 

 line. D. 15; A. 30 in two, 31 in one; serrae 34, 35, 36; eye about 1.5 

 in the snout, 5-5.5 in the head, 2-2.2 in the interorbital; lower pos- 

 terior margin of the second interorbital subtruncate, leaving a seg- 

 ment of a circle of the cheek naked. Gill-rakers minute. 

 5796 a. C. M. 40 mm. Bastos on the Rio Alegre, a tributary of the 



Guapore. June 26, 1909. Haseman. 



Head 2.75; depth 2.25; D. 17; A. 35; serrae 26; eye 3 in the head; 

 interorbital 4. Distal half of dorsal and caudal, distal half of anal 

 lobe and anal margin jet black; sides spotted. 



This specimen differs conspicuously from the adult of elongatus. 

 Many of its characters are, howe^•er, undoubtedly due to its youth, 

 and in all likelihood it is the young of elongatus. 



16. Serrasalmo gibbus Castelnau. 



Serrasalmo gibbus Castelnau, Anim. Am. Sud, Poiss, 1855, pi. 38, fig. i (Araguay); 

 Eigenmann & Eigenmann, Proc. U. S. Nat. Mus., Vol. XIV, 1891, p. 60. 



Serrasalmo gibbus Gunther, Cat. Fishes Brit. Mus., Vol. V, 1864, p. 366; Eigen- 

 mann, Reports Princeton Univ. Exp. Patagonia, Vol. Ill, 1910, p. 442. 



Habitat. — Araguay. 



Known only from Castelnau's figure. It is probably a- synonym 

 of elongatus. 



17. Serrasalmo hoUandi^ Eigenmann, sp. nov. (Plate XLVIII.) 

 5792 a. C. M. About 130 mm., 109 mm. to end of scaled portion 



of caudal. Maciel, Rio Guapore, July 23, 1909. Haseman. 



Depth 2.16; head 3.33; D. 16; A. 32; serrae 37; scales 31-86-27; 

 eye 3.66 in head, snout 4, interorbital 2.6; depth of caudal peduncel 

 3.33. Origin of dorsal about an orbital diameter nearer snout than 

 end of lateral line; distance of dorsal from upper caudal fulcra equals 

 length of head; base of dorsal equals length of head less snout and half 

 the orbit, but little greater than its distance from the adipose; origin 

 of anal equidistant from the base of the last ray and the middle of 

 the pectoral; origin of ventrals a little nearer tip of snout than the 

 distance between snout and predorsal spine. 



Elongate, compressed; dorsal and ventral profiles about equally 

 curved; dorsal profile but little depressed over eye, snout not very 

 blunt, the lower jaw scarcely entering profile; occipital process about 



« Named for my friend, Dr. VV. J. Holland, Director of the Carnegie Museum. 

 C H. Eigenrnann. 



