156 OSTARIOPHYSI. 
B. 40 to 50 scales in a longitudinal series. 
Diameter of eye 3 to 34 in the length of head (in specimens measuring up to 
55 mm.); caudal deeply notched, the middle rays 4 as long as the 
longest. . 1 1 we ee ee ee ee ew www ww 12. formosus. 
Diameter of eye 4 to 5 in the length of head (in specimens measuring up to 
80 mm.); caudal moderately notched, the middle rays ? as long as the 
longest . 2. 6 6 ue ee ww ww ew we ew www we «LB. arte cus. 
1. Notropis boucardi. (Tab. XXV. figg. 4, 5.) 
Moniana nitida (non Alburnus nitidus, Kirtland), Girard, Proc. Ac. Philad. 1856, p. 21°. 
Leuciscus boucardi, Ginth. Cat. Fish. vii. p. 485 (1868) *. 
Graodus nigroteniatus, Giinth. 1. c.*. 
Rutilus boucardi, Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 247°. 
Notropis nigroteniatus, Jord. & Everm. t. c. p. 264’. 
Notropis braytoni, Jord. & Everm. 1. c.£; Meek, Publ. Columbian Mus., Zool. v. 1904, p. 65%. 
Notropis boucardi, Meek, t. c. p. 67°. 
Depth of body 34 to 44 in the length, length of head 33 to 43. Diameter of eye 34 to 43 in the length of 
head. Mouth little oblique; lower jaw included within the upper; snout obtuse. Dorsal 9, with 7 
branched rays. Anal 8-10, with 6 to 10 branched rays. Ventrals inserted nearly below the origin of 
dorsal, which is about equidistant from tip of snout and base of caudal. 35 to 39 scales in a longitudinal 
series, 6 or 7 in a transverse series from origin of dorsal fin to lateral line, 3 or 4 between lateral line 
and base of ventral fin. Lateral lina complete. Caudal peduncle about twice as long as deep. Usually 
a dark lateral stripe ending in a caudal spot. 
Hab. Mexico, rivers of Nuevo Leon and Tamaulipas and northern tributaries of the 
Rio Balsas : 
Cadereita’ and Rio San Juan‘ (Meek) in Nuevo Leon; Rio Conchos’ and 
Rio Soto Marina’ (Meek) in Tamaulipas; Yautepec®, Cuautla®, Cuernavaca * 
(Boucard), Atlixco®®, Puente de Ixtla® (Meek), Matamoros®, Jojutla® and 
Chietla 8. 
Here described from a series of specimens measuring up to 100 mm. in total length. 
The examples figured are the types of Leuciscus boucardi (fig. 4) and Graodus 
nigroteniatus (fig. 5). 
2. Notropis orca. 
Notrenis orca, Woolman, Bull. U.S. Fish. Comm. xiv. 1894, p.56'; Jord. & Everm. Bull. U.S. Nat. 
Mus. xlvii. 1896, p. 289°. 
Hab. Rio Grande at El Paso, Texas. 
3. Notropis nazas. 
Nototropis nazas, Meek, Publ. Columbian Mus., Zool. v. 1904, p. 70, fig. 19°. 
Depth of body 4 to 44 in the length, length of head 4. Diameter of eye 33 to 3% in the length of head, 
Mouth little oblique; lower jaw included within the upper; snout rather pointed. Dorsal 9, with 7 
branched rays. Anal 9. Ventrals inserted in advance of the origin of dorsal, which is a little nearer 
to the base of caudal than to the tip of snout. 48 to 54 scales in a longitudinal series, 9 or 10 in a 
