THE AMERICAN TERTAGONOPTERINAE. 191 
the eye; mandible equal to the eye, 2.7 in the head. Premaxillary with two 
conical teeth in the outer row and nine tricuspid teeth in the inner row. Maxil- 
lary without teeth. Dentary with a graduated series of about nine tricuspid 
teeth. 
Gill-rakers 7 + 9. 
Anal sheath probably short or lacking. Lateral line with pores developed 
on the first 7 scales. 
Origin of the dorsal one half the length of the eye nearer to the caudal 
than to the snout, penultimate ray one third the longest which is 3.67 in the 
length. Caudal longer than the head. Origin of the anal on the vertical from 
the seventh dorsal ray. Anal emarginate, rays fine and close together, longest 
ray 1.8 in the base of the fin. Ventrals on the vertical from the second or third 
seale in front of the dorsal; ventrals not quite reaching the anal. Pectorals 
barely reaching the ventrals. 
Caudal spot intense and round, not continued on the middle caudal 
rays. No humeral spot. Lateral stripe silvery, without dark pigment. Fins 
all hyaline. Suborbitals and the scales over the lateral stripe silvery iridescent. 
The specimen may be badly faded, as even the usual dusky coloration on the 
back is lacking. 
14. HypHESSOBRYCON TAUROCEPHALUS Ellis. 
Plate 29, fig. 3. 
Hyphessobrycon taurocephalus Exuis, Ann. Carnegie mus., 1912, 8, p. 151, pl. 1, fig. 4 (Serrinha Parana). 
Hasitat.— Upper Iguassu. 
Specimens examined. 
Number of Size 
Catalogue number specimens in mm. Locality Collector 
3007 C. Type 1 55 Serrinha Parana, Rio Iguassii Haseman 
3008 C. Paratypes 32 30-46 Serrinha Parana, Rio Iguassti Haseman 
3009 C. Paratypes 22 30-45 Porto Uniao, Rio Iguassti Haseman 
3010 C. Paratypes 13 27-36 Porto Uniao, Rio Iguassti Haseman 
Head 3.8-4; depth 3; D. 11; A. 14 to 16; scales 5 or 6-32 to 36-4 to 5. 
Eye 3 to 3.25; interorbital much wider than the eye, 2.2 in the head. 
Little compressed, depth of the head at the base of the occipital process 
1.25 in the greatest depth. Preventral region rounded, without complete series 
of median scales. Predorsal region rounded. 
