32. CHARACINID^ TETRAGONOPTERUS. 
255 
the place of the Salmonidcc and Cyprhiidcc of the Northern Hemisphere. 
A single species reaches the United States. 
{Characinidw Gunther, vii, 278-380.) 
* Adipose fin present. 
t Dentition complete in both jaws; gill-openings wide, the membranes not at- 
tached to the isthmus; nasal openings of each side close together; teeth 
compressed, notched. {Tctragonoptermce.) 
t Anal fin elongate (rays 20-50); belly in front of ventrals rounded ; premaxillary 
teeth in a double series; a single series of teeth in lower jaw, with no conical 
teeth behind it ; no canine teeth; gill-rakers setiform..TETKAGOXorTERUS, 114. 
114.— TETKAOOl^OPTERirS Cuvier. 
{Astyanax B. &. G. ; Poccihirichthys Gill.) 
(Artedi; Cuvier, M^m. du Mus. iv, 455, 1818: type Tctragonoptcrus argcntcns Ciiv.) 
Body oblong or elevated, compressed, covered with moderate scales. 
Belly rounded. Cleft of mouth medium. Anterior teeth strong, incisor- 
like; lateral teeth small. Premaxillary and mandibular teeth subequal 
in size, with a compressed, notched crown, the former in a double, the 
latter in a single, series. Maxillary with few teeth. Xostrils of each 
side close together, separated by a valve only. Lower pharyngeals very 
slender, curved, approaching the form in Cyprinidw^ armed with a single 
series of slender, hooked teeth. Gill-openings wide, the membranes 
free from the isthmus and from each other. Gill-rakers setiform. Dor- 
sal fin midway of body, abbve or just behind ventrals. Anal fin long. 
Species about 40, in all the warmer j^arts of America, 
four-angled; -repov^ fin or wing; of no special application to this group, 
the original word used by Klein and Artedi being Tetragonoptrus.) 
a. Bodj’ oblong, moderately elevated, the depth less than half length. (Jslyanax Baird 
& Girard.*) 
429. T. ai’SCiitafMS (Baird & Girard) J. & G. 
Olivaceous; a broad silvery band along sides; a black spot at base of 
caudal, running up on the fin. Body oblong, compressed. Snout blunt, 
lower jaw included. Dorsal inserted above ventrals. Pectorals reach- 
ing ventrals, the latter to vent. Head 4 in length; depth .3. D. 10; A. 
21; scales 6-38-C. Arkansas to Mexico; probably abundant; the north- 
ernmost representative of the family. 
(Astyanax argeutatus B. & G. Proc. Acad. Nat. Sci. Phila. vii, 27, 18.54: Astyanax 
argenlatus Grd. U. S. Mex. Bound. Surv. Ichth. 74; Giinthei', v, 380.) 
* Baird &. Girard, Proc. Acad. Nat. Sci. Phila. vii, 2C, 18.54 : typo Astyanax argeutatus 
B. &, G. {adtifavac, a son of Hector.) 
