32. CHARACINID^ TETRAGONOPTERUS. 255 



the place of the Salmonidce aud Cyprinidcvoi the Xorthern Hemisphere. 

 A single species reaches the United States. 



{CharacUtidw Giiuther, vii, 278-380.) 



"Adipose fin present, 

 t Dentition complete in both jaws; gill-openings ■wide, the membranes not at- 

 tached to the isthmns ; nasal openings of each side close together; teeth 

 compressed, notched. {Tclragonoptannce.) 

 tAnal fin elongate (rays 20-50); belly in front of ventrals rounded ; preniaxilluTV 

 teeth in a double series; a single series of teeth in lower .jaw, with no coniciil 

 teeth bellind it ; no canine teeth; gill-rakers seti form.. Tktraooxopterus, 114. 



114.— TETRAGONOPTERUS Cuvier. 

 {Aatyanax B. & G. ; Facihtrklithns Gill.) 



(Artedi; Cuvier, M^m. du Mus. iv, 455, 1818: type Tctragonopterus argcnteus Cuv.) 



Body oblong or elevated, comin-essed, 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. Maxillaiy 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- 

 sjil lin midway of body, ab&ve or just behind ventrals. Anal tin long. 

 Species about 40, in all the warmer parts of America. [r—jidyurM,^^ 

 four-angled ; -z^pw^ tin or wing; of no special application to this group, 

 the original word used by Klein and Artedi being Teira(ionoptrm.) 



a. Hody oblong, moderately elevated, the depth less than half length. {Jsli/anax Baird 

 & Girard.*) 



429. T. arg^eiitatiis (Baird & (iirard) J. & G. 



Olivaceous; a broad silvery band along sides; a black spot at base of 

 caudal, I'unning uj) on tlic tin. Body oblong, compressed. SiumiI blunt, 

 lower jaw included. Dorsal inserted above ventrals. Pectorals reach- 

 ing ventrals, the latter to vent. Head 4 in length; de])tli 'A. 1). 10; A. 

 21; scales ()-.>8-G. Arkansas to Mexico; probably abundant; the north- 

 ernmost representative of the family. 



(Aatyanax argcntatnit B. &. G. Proc. Acad. Nat. Sci. Phila. vii, 27, 18.'')4: Axiyanax 

 argenfatiis Grd. U. S. Mex. Bound. Surv. Ichth. 74; GUnther, v, :J80.) 



* Baird & Girard, Proc. Acad. Nat. Sci. Phila. vii, 26, 18.54 : type Aatyanax argentaUis 

 B. &, G. (adTi'dva^, a son of Hector.) 



