266 CALIFORNIA ACADEMY OF SCIENCES. 



io. Spheroides annulatus (Jenyns). 



Five specimens, 3 to 3^ in. long, from La Paz. The 

 bar at base of pectoral is indistinct, and there is a pale 

 edging at tip of caudal. 



IV. 



DESCRIPTION OF A NEW SPECIES OF CHARACONDON FROM 

 TEPIC, MEXICO. 



Characodon eiseni Rutter, new species. 



Head 3^ ; depth 3^ ; eye 3. Dorsal n to 13; anal 

 13; scales 30 to 32, 12. Snout shorter than eye, lower 

 jaw projecting. About nine teeth in upper jaw and about 

 14 in lower. Teeth strongly bicuspid, the villiform teeth 

 not developed. Mouth almost vertical when closed, man- 

 dible about half length of eye. Interorbital space flat, 

 the anterior part equal to orbit, wider posteriorly. In- 

 sertion of dorsal in middle of total length ; anal inserted 

 under 4th ray of dorsal. Pectoral reaching past inser- 

 tion of ventral. Tips of depressed dorsal and anal in 

 vertical through middle of caudal peduncle. Caudal 

 broad, truncate, length of middle rays equal to length of 

 top of caudal peduncle. Head about % of total; great- 

 est depth of body above ventrals. Depth of caudal pe- 

 duncle yi its length. Color, in alcohol: Male with a 

 broad indefinite lateral band; female with dark blotches 

 on sides which in one of three specimens form distinct 

 cross-bands. 



This species is most closely related to Characodon 

 variatus Bean, which is found in the headwaters of the 

 same basin. It differs from that species in having fewer 

 rays and scales, much fewer teeth, larger eye, much more 

 posterior position of dorsal, and in color. 



This description is based on four specimens (No. 4999, 



