FALCULA.— NOTEOPIS. 155 



eye, the diameter of which is 5 to 6 in the length of head ; infcerorbital width Sg to 3| in the length of 

 head. Mouth terminal, oblique. Dorsal 10, with 7 branched rays ; origin equidistant from tip of snout 

 and base o£ caudal or a little nearer the former ; longest ray f to -f the length of head. Anal 10. 

 Ventrals inserted below or in advance of the origin of dorsal. 45 to 50 scales in a longitudinal series, 

 8 in a transverse series from origin of dorsal to lateral line, 4 or 5 between lateral line and base of 

 ventral. Silvery, back darker ; fins pale. 



Hah. Mexico, Rio Lerma System : 



Lake Chapala ^^ (^Buller) ; Ojo de Agua, Michoacan [Mexico Mus.). 



Here described from four specimens, 130 to 190 mm. in total length. 



12. NOTEOPIS, Eafin., 1818. 

 Notropis, Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 254. 



This genus differs from Leuciscus in the smaller number of pharyngeal teeth, in 

 one or two series, 4, 0-2 — 0-2, 4. 



The scales are large (30 to 60 in a longitudinal series), and the ventral fins are 

 8-rayed. 



A large number of species of small fishes from the United States east of the Eock}' 

 Mountains and from Mexico. 



Synopsis of the Mexican Species. 



I. Mouth subterminal, the lower jaw included. 



.'55 to 39 scales in a longitudinal series . 1. boucarcU. 



42 scales in a longitudinal series 2. orca. 



48 to 54 scales in a longitudinal series 3. nazuH. 



54 to 60 scales in a longitudinal series 4. salUei. 



II. Mouth terminal, oblique, with the jaws equal anteriorly. 

 A. 32 to 40 scales in a longitudinal series. 



1. Lateral line complete or absent ou a few scales posteriorly. 



a. Caudal peduncle .2J as long as deep 5. chihuahua. 



b. Caudal peduncle not more than twice as long as deep. 



a. Diameter of eye 2^ (young) to 3i (adult) in the length of head; 



82 to 36 scales in a longitudinal series 6. macrostomm. 



/3. Diameter of eye 3^ to 5 in the length of head ; 34 to 40 scales 

 in a longitudinal series. 



Males with several dark cross-bars ; anal fin of 8 or 9 rays 7. oriiatus. 



Males with a dark vertical bar behind the head ; aual fin of 9 or 10 rays; 



length of head 3f to 4 in the length of the fish 8. lutrensis. 



Males with a dark vertical bar behind the head; anal fin of 10 to 12 rays; 



length of head 4 to 44 in the length of the fish 9. f/armani. 



2. Lateral line incomplete, not continued beyond the ventral fins. 



38 scales in a longitudinal series 10. santamarue. 



33 to 35 scales in a longitudinal series 11- calientifi. 



X 2 



