CHIEOSTOMA. 59 



90 ram. in total length. Dr. Meek's type has V, I 10 dorsal rays, I 17 anal rays, and 

 48 scales in a longitudinal series. 



o. Chirostoma arge. 



Esloparsum arge, Jord. & Snyd. Bull. U.S. Pish. Comm. xix. 1899, p. ]33, fig. 12 (1901)'; 



Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1900, p. 3158". 

 Chirostoma arge, Meek, Publ. Columbian Mus., Zool. v. 1904, p. 171, fig. M\ 



Depth of body 4^ to 5 in tho length, length of head 4| to 4|. Snout as long as eye, tho diameter of which 

 is 3.| in the length of head and nearly equal to the interorbital width. Teeth small ; lower jaw very 

 slightly projecting ; maxillary very slightly exposed distally, extending to the vertical from the anterior 

 margin of eye. 11 or 12 gill-rakers on the lower part of the anterior arch. Scales with entire edges, 

 36 to 42 in a longitudinal series. Dorsal III-IV, I 8-9 ; spinous dorsal in advance of anal, its origin 

 nearly equidistant from tip of snout and base of caudal. Anal I 14-17. Pectoral about | the length of 

 head, extending to or a little beyond the base of ventrals. Caudal forked. Caudal peduncle 2 to 2J as 

 long as deep. 



Hah. Mexico, Rio Lerma System : 



Aguas Calientes ^ ^ ; Lagos ^. 



Here described from several specimens, measuring up to 70 mm. in total length, 

 from Aguas Calientes [Jordan) and Lagos [Meek). 



4. Chirostoma jordani. 



Chirostoma jordani, Woolman, Bull. U.S. Fish. Comm. xiv. p. 6.2, t. 2 (1895)'; Jord. & Everm. 



Bull. U-S. Nat. Mus. xlvii. 1896, p. 793' ; Meek, Publ. Columbian Mus., Zool. v. 1904, 



p. 169, fig. 52'. 

 Chirostoma mezquital. Meek, t. c. p. 170, fig. 53 ^ 



Depth of body 4 to .5 in the length, length of head 4^ to 4|. Snout shorter than eye, the diameter of which 

 is 3 to 3i in the length of head ; interorbital width about 3 in the length of head. Teeth small ; lower 

 jaw very slightly projecting; maxillary not exposed, not quite reaching the vertical from the anterior 

 margin of eye. 10 gill-rakers on the lower part of anterior arch. Scales with entire edges, 38 to 42 in 

 a longitudinal series. Dorsal III-IV, I S-10 ; origin of spinous dorsal nearly equidistant from tip of 

 snout and base of caudal ; last dorsal spine inserted above the origin of aual. Anal I 16-19. Pectoral 

 a little shorter than the head, extending to above the middle of ventrals. Caudal peduncle twice as 

 long as deep. 



Ilah. Mexico, Eio Mezquital and Rio Lerma Systems, Valley of Mexico : 



Durango * ; Aguas Calientes ^ ; Lagos ^ ; Salamanca ^ ; Lake Chapala ^ 3 ; Acam- 

 baro 3 ; Lake Cuitzeo ^ ; Texcoco ^ ; Chalco ^ ; City of Mexico ^ ^ • Yautepec ^. 



Here described from specimens from Salamanca {Woohnan) and Acambaro {Meek), 

 measuring up to 65 mm. in total length. 



5. Chirostoma breve. (Tab. X. fig. 3.) 



Chirostoma breve, Steind. Denksclir. Ak. Wien, Ixii. 1895, p. 526, t. 2. fig. 2 \ 



Chirostoma laharca, Meek, Publ. Columbian Mus., Zool. v. 1904, p. 173'. 



Depth of body 4 to 4| in tho length, length of head 4 to \\. Snout as long as or a bttle longer than the eye, 



I 2 



