32. CHARACINID^ TETRAGONOPTERUS. 255 



the place of the Salmonidcc and Cyprinidcc of the Northern Hemisphere. 

 A single species reaches the United States. 



(Charatinida Giiuther, 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. (Tclragonoptcrince.) 



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 .. TETRAGONOPTERUS, 114. 



114. TETRAGONOPTERUS Cnvier. 



(Astyanax B. & G. ; Poccilurichthys Gill.) 

 (Artedi; Cuvier, Me"m. clu Mus. iv, 455, 1818: type Tctragonopterus argen-teus Cuv.) 



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. Nostrils of each 

 side close together, separated by a valve only. Lower pharyngeals very 

 slender, curved, approaching the form in Cyprinidce, 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, above or just behind veutrals. Anal fin long. 

 Species about 40, in all the warmer parts of America. (Ts-pdfwvoz, 

 four-angled ; nspw, fin or wing; of no special application to this group, 

 the original word used by Klein and Artedi being Tetragonoptrus,) 



a. Body oblong, moderately elevated, the depth less than half length. (Astyanax Baird 

 & Girard.*) 



429. T. arg-entatus (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 ; depths. D. 10; A. 

 21; scales 6-38-6. Arkansas to Mexico; probably abundant; the north- 

 ernmost representative of the family. 



(Astyanax arycntattts B. & G. Proc. Acad. Nat. Sci. Phila. vii, 27, 1854: Astyanax 

 argtntatus Grd. U. S. Mex. Bound. Surv. Ichth. 74; Giinther, v, 380.) 



* Baird & Girard, Proc. Acad. Nat. Sci. Phila. vii, 26, 1854 : type Astyanax argentatus 

 B. &. G. (a6n>dvaz, a son of Hector.) 



