1906.] NATURAL SCIENCES OF PHILADELPHIA. 335 



trenchant. Snout convex. Tongue small, a little back, narrow, and 

 a little free. Interorbital space narrowly convex. Gill-opening car- 

 ried forward nearly opposite anterior margin of orbit. Rakers 6 + 12?, 

 slender, fine, longest a little longer than filaments and also present on 

 lower portion of external arch. Isthmus rather broadly triangular. 

 Scales striate. Vent close in front of anal. Color in alcohol more or 

 less brownish, back more brown than lower surface and body ^-ith 

 silvery wash. A leaden lateral streak from head opposite eye straight 

 to base of caudal. Fins plain pale brownish. Eye brassy. Length 

 1^^ inches. 



Cope was entirely mistaken when stating that the inferior limb of 

 the external branchial arches was without rakers. 



Hemigrammus sclimardae (Steindachner). 



Head 3; depth 2f ; D. iii, 9; A. iv, 21?; about 30? scales in a lateral 

 covnit from gill-opening to caudal, including those on latter; snout 4^ 

 in head, measured from tip of upper jaw; eye 2^; maxillary 2f ; inter- 

 orbital space 3. Color in alcohol brownish, scales fallen leaving a 

 narrow silvery lateral band extending from shoulder to base of caudal. 

 No blackish blotch at base of caudal, which while a little darker than 

 rest of fin is not darker than peduncle. These conditions may all be 

 due to the preservative. Length If inches. A single small example 

 in poor condition from the Peruvian Amazon. Coll. Prof. J. Orton. 



Hemigrammus interruptus (Lutken). 



Hemigramvivs luetkenii Cope, Proc. Amer. Philos. Soc. Phila., XXXIII, 1894 

 (January 5), p. 91. In the Jacuhy (Brazilian pro\'ince of Rio Grande do 

 Sul). H. H. Smith. 



The large series from the Jacuhy, Brazilian province of Rio Grande 

 do Sul, and collected by H. H. Smith, shows : Head 3 to 3|; depth 2J to 

 2f ; D. Ill, 9; A. IV or v, 18, i to 22, i, usually with 21, occasionally 22, 

 sometimes 18, and rarely 20; scales 30 to 33 in lateral line to base of 

 caudal, 2 or 3 more on latter, former count usually 33, frequently 32 

 or 31, and rarely 30; 11 or 12 scales in a transverse series obliquely 

 back from origin of dorsal; 12 or 13 scales before dorsal; eye 2h to 3 in 

 head, measured from tip of upper jaw; length of specimens If to 3 

 inches. Gill-rakers about 8 + 14. 

 Hemigrammus robustulus Cope. Fig. 24. 



Proc. Amer. Pliilos. Soc. Pliila., XI, 1869-70 (August 17, 1870), p. 561- 

 Nos. 8,037 (type) to 8,052, A. N. S. P., cot}T)es. Pebas, Equador. John 



Hauxwell. Cope, I.e., XVII, 1877-78 (May 17, 1878), p. 690. Peruvian 



Amazon. Prof. J. Orton. 



Body strongly compressed. Rami of mandible but little elevated 

 inside mouth. Tongue rather flat, rounded, compressed and a little 



