i24 Field Columbian Museum — Zoology, Vol. V. 



nent; outer series of teeth enlarged, firm, and bicuspid; snout 4 in 

 head; eye 3; dorsal fin high, its origin slightly nearer base of caudal 

 than tip of snout; about half of the fin in front of origin of anal; pec- 

 toral fin 1 x 4 in head; ventral fin i^ - , caudal peduncle long and 

 slender, its least depth 2 in head; the caudal fin slightly emarginate. 



Color light brownish with 8 or 9 spots along the middle of the sides, 

 occasionally forming short bars, each sometimes broken in the middle, 

 forming two bars; usually a large black spot about the size of pupil 

 above and a little forward of the origin of the anal; fins all plain. 

 Length about 4 inches. 



One female 2.70 inches in length contained 21 young, each .40 inch 

 in length. The voung are born the latter part of May. 



50. Cyprinodon Lacepede. 

 Pursey Minnows. 



Cyprinodon Lacepede, Hist. Nat. Poiss., v, 486, 1803. (Type, 

 Cyprinodon variegatus Lacepede.) 



Prinodon Rafinesque, Analyse de la Nature, 1S15, 88. (Type, 

 Cyprinodon variegatus Lacepede.) 



Body very short and stout, the dorsal region elevated; mouth 

 small; teeth incisor-like, tricuspid, in a single series; scales large, 

 dorsal fin inserted in advance of anal; ventrals small or wanting; gill 

 openings restricted; the opercle above adnate to shoulder girdle: ali- 

 mentary canal little longer than the body. Oviparus. Spawning 

 time June and Jul v. 



This genus comprises a group of small chubby fishes inhabiting 

 fresh or brackish waters. They are found living in small springs and 

 isolated bodies of water in the desert regions of southwestern United 

 States and northern half of Mexico, where no other fishes are found. 

 The species are very variable. It would perhaps be quite as well to 

 regard the species listed below as varieties of Cyprinodon elegans. 



KEY TO THE SPECIES OF CYPRINODON. 



a. Color markings on the side with a tendency to page 



form cross-bars. 

 b. Scales 28 in the lateral series; dorsal rays 8 or 

 9 ; anal 8 to 10. 

 c. Dorsal fin yellow; caudal fin light, much 



speckled with darker eximins 125 



cc. Dorsal fin dark, or with anterior half yel- 

 lowish; caudal fin plain, not speckled with 

 darker elegans 125 



