164 OSTAEIOPHTSI. 



1. Couesius adustus. 



Coneshis adushis, Woolman, Bull. U.S. Fish. Comm. xiv. 189-1., p. 57^ Jord. & Everm. Bull. 

 U.S. Nat. Mus. xlvii. 189G, p. 335'; Meek, Publ. Columbian Mus., Zool. v. 1904, 

 p. 82'. 



Ilab. Mexico, Rio Conches in Chihuahua ^ -. 



21. HYBOPSIS, Agass., 1854. 

 Hybopsis (part.), Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 314. 



Differs from Yuriria in having tlie hody less compressed, the snout obtuse, the mouth horizontal and sub- 

 terminal or inferior, the isthmus wider, and the ventral fins 7- or S-rayed. 



About fifteen species from the United States, from the Great Lakes to the Eio 

 Grande and its southern tributaries. 



1. Hybopsis aestivalis. 



Gohio (estivalis, Girard, Proc. Ac. Philad. 1856, p. 189 \ and U.S. & Mex. Bound. Surv., Fish. p. 49, 



t. 57. figs. 17-29 (1859) \ 

 Hybopsis (estivalis, Jord. & Kvcrm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 316 '3 Meek, Publ. 



Columbian Mus., Zool. v. 1904, j). 81 '. 



Depth of body 4 to 5 in tin; leogih, length of head 4. tSnout as long as postorbital part of head ; diameter of 

 eye 4 in the length of head. Dorsal 9, with 7 branched rays ; origin nearer to tip of snout than to base 

 of caudal ; longest ray shorter than the head ; free edge concave. Anal S-9. Pectorals sometimes 

 nearly reaching the veotrals, which are inserted below the origin or anterior part of dorsal. 33 to 36 

 scales in a longitadinal series, 5 or ti in a transverse series from origin of dorsal to lateral line, 3| or 4 

 between lateral line and base of ventral. Caudal peduncle twice as long as deep. Upper part of body 

 with small dark spots ; a dusky strij)e on each caudal lobe. 



Hob. Mexico, Rio San Juan in Nuevo Leon ^ ^ ■* ; Rio Conchos in Tamaulipas * {Meek). 

 Here described from six specimens, measuring up to 65 mm. in total length. 



2. Hybopsis sterletus. 



Ceratichthys sterletus, Cope, in Wheeler's Surv., Zool. v. p. 652, t. 27. fig. 3 (1876). 



Depth of body 5^ in tlic length, length of head 4. Snout nearly as long as postorbital part of head ; diameter 

 of eye 4;^ in the length of licad. Dorsal 9, witli 7 branched rays ; origin nearer to tip of snout than to 

 base of caudal ; longest ray nearly as long as the head ; free edge concave. Ana) 9. Pectorals extending 

 to the vcntrals, which are inserted below the origin of dorsal and reach the anal. ;jy scales in a longi- 

 tudinal series, 5] in a transverse series from origin of dorsal to lateral lino, 4 between lateral line and 

 base of ventral. Caudal peduncle twice as long as deep. Coloration uniform ; tins pale, 



llab. Rio Grande : 



San lldefonso ' ; Juarez ( Woolmari). 



Here described from a single specimen of 40 mm. 



