ZOOGONETICUS.— LIMNUEGUS. 87 



Zoogoneticvs robustus, Meek, Publ. Columbian Mus., Zool, iii. 190.2, p. 92', and v. 1904, p. 113, 



fig. 31 '. 

 Zoogonetims maculatus, Regan, Ann. Mag. N. H. (7) xiii. 1904, p. 256'. 



Depth of body 3 to 3| in the length, length of head 3 to 3-}. Snout as long as or longer than eye, the 

 diameter of which is 4 to 5 in the length of head ; intcrorbital width 2i to 2j in the length of head. 

 Lower jaw projecting. 36 to 39 scales in a longitudinal series. Dorsal 13-14 ; origin nearly equidistant 

 from prasopcroulum and base of caudal. Anal 14-16 ; origin a little behind that of the dorsal. Pectoral 

 ^ to I the length of head. Caudal subtruncate. Body usually with irregular dark spots ; fins 

 immaculate. 



Ilal). Mexico, Eio Lerma System : 



Guanajuato 1 ; Rio Grande de Santiago ^ {Buller) \ Lake Chapala^^; Lake 

 Cuitzeo 3 4 . Lake Patzcuaro 3 4 . Zirahuen ^ 4. 



Here described from several specimens from tlie Rio Grande de Santiago, Lake 

 Chapala, and Lalie Patzcuaro, measuring up to 145 mm. in total length. 



6. LIMNURGUS, Giindi., 1SG6. 



Limnurgua, Giinth. Cat. Fish. vi. p. 309 (18G6). 



Girardinidithys, Jord. & Everm. Bull. U.S. Nat. Mas. xlvii. 1896, p. &m. 



Viviparous. Anal fin of the male with the anterior five or six rays .short, stiff, and subequal, separated by a 

 more or less distinct notch from the rest of the fin. Mouth small, with short lateral cleft ; rami of the 

 lower jaw firmly united; minute teeth in bands, with an outer series of enlarged fixed teeth which are 

 usually spear-shaped, but may have their apices truncate or even notched. 



A single species from the Valley of Mexico. 



1. Limnurgus imiominatus. (Tab. XIL fig. l.) 



Lucania sp., Girard, Proc. Ac. Philad. 1859, p. 118 '. 



Girardinichthys imiominatus. Bleak. Cyprin. p. 484 (1860) '; Jord. & Everm. Bull. U.S. Nat. Mus. 



xlvii. 1896, p. 666 ' ; Meek, Publ. Columbian Mus., Zool. v. 1904, p. 116 \ 

 Limnurgus variegatus, GUnth. Cat. Fish. vi. p. 309 (1866) '. 

 Characodon geddesi, Regan, Ann. Mag. N. H. (7) xiii. 1904, p. 257'. 



Depth of body 21 to 85 in the length, length of head 3| to 4. Snout as long as eye, the diameter of which 

 is 4 to 4| iu the length of head ; intcrorbital width 2\ to 2|- in the length of head. 39 to 43 scales in 

 a longitudinal series. Dorsal 18-23; origin equidistant from eye(<:T)or operculum ($) and base of 

 caudal. Anal 20-26 ; origin a little l)chind that of the dorsal. Pectoral | the length of head. Caudal 

 subtruncate. Body with irregular dark spots or narrow vertical bars. 



Eal. Mexico, Valley of Mexico : 



City of Mexico!; Lake Chalco* {Meek); Lake Tezcoco ^ {Geddes) \ 

 Xochimilco ■*. 



Here described from several specimens, measuring up to 75 mm. in total 

 length. 



