62 PEECESOCES. 



10. Chirostoma pronielas. 



Chirostoma promehis, Jord. & Suyd. Bull. U.S. Fisli. Comm. xix. 1899, p. 136, fig. 14' ; Jord. & 

 Everm. Bull. U.S. Nat. Mus. xlvii. 1900, p. 3160 = ; Meek, Publ. Columbian Mus., Zool. v. 

 1904, p. 177 \ 



Allied to C. lucius, but with the lower jaw shorter than the upper. Dorsal IV, I 11. Anal I 19-20. Scales 

 with crenate edges, 53 to 56 in a longitudinal series. 



Hah. Mexico, Eio Lerma System: 

 Lake Chapala ^ ^. 



11. Chirostoma lucius. 



Chirostoma lucius (part.), Bouleng. Ami. Mag. Nat. Hist. (7) v. 1900, p. 54'. 



Chirostoma crystaUinmn, Jord. & Siiyd. Bull. U.S. Fish. Comm. xix. 1899, p. 139, figs. 16 & 17 



(1900) ''; Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1900, p. 3162'. 

 Chirostoma lucius, Meek, Publ. Columbian Mus., Zool. v. 1904, p. 178, fig. 60'. 



Depth of body 4 in the length, length of head Sj. Snout 1| as long as eye, the diameter of which is 5] in 

 the length of the head ; interorbital width 4 in the length of head. Teeth rather small ; lower jaw 

 projecting, ti the length of head ; maxillary exposed distally, extending to the vertical from the anterior 

 margin of eye ; 20 gill-rakers on the lower part of the anterior arch. Scales with crenate edges, 

 52 in a longitudinal series. Doisal VI, I 11 ; spinous dorsal in advance of the anal, its origin nearer to 

 base of caudal than to tip of snout. Anal I 20. Pectoral 4 the length of head, extending nearly 

 to above the middle of ventrals. Caudal forked. Caudal peduncle twice as long as deep. 



Hah. Mexico, Eio Lerma System : 



Guadalajara ^ ; Lake Chapala ^ ^ [Buller). 



Here described from the type of the species, measuring 200 mm. in total length. 

 Jordan and Snyder give the following numbers for C. crystallinum: — Dorsal IV-V, 

 I 11-13. Anal I 18-24. 56 to (30 scales in a longitudinal series. 



12. Chirostoma diazi. 



Clarostoma diazi, Jord. & Snyd. Bull. U.S. Fish. Comm. xix. 1899, p. 137, fig. 15 (1900) ' ; Jord. & 



Everm. Bull. U.S. Nat. Mus. xlvii. 1900, p. 316P. 

 Chirostoma sphyrfuna, Meek, Publ. Columbian j\lus., Zool. v. 1904, p. 177, fig. 59'. 



Closely allied to the preceding species, but with smaller scales (tiO to 75 in a longitudinal series); dorsal scales 

 very small and irregular, 21 to 27 in a series between the two dorsal fins. Dorsal IV-V, I 11-12. 

 Anal I 20-22. 



Ihilj. Mexico, Rio Lerma System : 

 Lake Chapala ^. 



13. Chirostoma ocotlane. (Tab. IX. fig. 1.) 



CJiirostoma lucius (part.), Bouleng. Ann. Mag. Nat. Hist. (7) v. 1900, p. 54'. 



Chirostoma ocotlane, Jord. & Snyd. Bull. U.S. Fish. Comm. xix. 1899, p. 140, fig. 18 (1901) = - 



Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1900, p. 3163 ' ; Meek, Publ. Cohmibiau Mus.^ 



Zool. V. 1904, p. 180, fig. 02 '. 



