1906.] NATURAL SCIENCES OF PHILADELPHIA. 435 



These examples seem to agree best with Tetragonopterus orientalis 

 Cope. The discrepancies in the depth of the body may be accounted 

 for by age, as the younger ones are more elongate. The anterior anal 

 rays are however much longer than the others. The eye was evidently 

 found to be 3 in the head, which also may possibly be attributed to 

 age, though my examples show it but a little less than interorbital 



Tetragonopterus viejita Valenciennes may be closely related or 

 identical, as it agrees in some respects, though it is impossible to con- 

 sider it on account of the imperfect diagnosis. 



Astyanax rutilus (Jenyns). 



Tetragonopterus rutilits Cope, Proc. Amer. Philos. Soc. Phila., XXXIII, 

 1S94 (January 5), p. 87. Brazilian province of Rio Grande do Sul. H. 

 H. Smith. 



Head 3f to 4^; depth 2f to 2f ; D. iii, 9, rarely in, 10; A. iv, 25, i to 

 IV, 28, 1, usually 25 or 26 developed rays, rarely 27 or 28; scales 35 to 40 

 in lateral line to base of caudal, usually 37 or 38, and 3 more on latter; 7 

 scales in an oblicjue series back from origin of dorsal to lateral line, 

 rarely 8; 5 or 6 scales, usually latter, from base of ventral to lateral 

 line; usually 6 scales from origin of anal, not counting those on base of 

 fin, to lateral line; 15 or 16 scales before dorsal; length of 12 specimens 

 ranging from 2 to 6 inches. 



I differ with Cope concerning the statement that this species re- 

 sembles Astyanax jequitinhonce (Steindachner). Most of my specimens 

 agree quite well with the latter's figure of A. rutilus. 



Astyanax jacuMensis (Cope). 



Tetragonopterus jacuhiensis Cope, Proc. Amer. Philos. Soc. Phila., XXXIII, 

 1894 (January 5), p. 88, PI. 6, fig. 6. Cotypes, 21,606 to 21,611; 21,683 

 to 21,703; 2f,912 (type) to 21,916, A. N. S. P. The Jacuhy (Brazilian 

 pro\'ince of Rio Grande do Sul). H. H. Smith. 



Head 3f ; depth 2^^ ; D. iii, 9; A. iv, 28, i; scales 35 in lateral line to 

 base of caudal, and 2 more on latter; 6 scales obliquely back from 

 origin of dorsal to lateral line; 8 scales in a vertical series between 

 origin of anal in lateral line; pectoral 1| in head; ventral If; snout 3f 

 in head measured from tip of upper jaw; eye 3^; maxillary 2f ; inter- 

 orbital space 2f. Body compressed. Predorsal and postventral 

 regions with Ioav median keel, pcstdorsal rounded and preventral with 

 a low keel on each side. Lips rather fleshy. Teeth as usual. Tongue 

 small, rounded, and little free in front. No maxillary teeth. Inter- 

 orbital space convex and rather broad. Gill-opening forward to 

 anterior nostril. Rakers 9 + 12?, longest | of filaments, which are 

 I of orbit. Scales striate. Tubes in lateral line simple. Color in 



