EMBRYOLOGY AND LARVAL DEVELOPMENT OF TELEOSTEAN FISHES. 415 



Young fish 12 mm. in length (fig. 15) exhibit practically all of the diagnostic 

 characters of the species. The back is becoming strongly elevated and the depth of 

 the body is proportionally greater than in the preceding stage. The caudal fin still 



Fig. 



-Newly hatched fish, actual length 4 mm. 



Fig. 13. — Larval fish 5 days after hatching:, actual length 5 mm. 





Fig. 14. — Young fish 9 mm. in length. 



Fig. 15. — Young fish u mm. in length. 



CYPRINODON VAKiaCATUS. 



remains more rounded than in the adult. The coloration is quite characteristic, although 

 the general color is lighter and the light vertical bands are more conspicuous than in 

 the adult. 



LUCANIA PARVA. RAINWATER-RSH. 



Spawning. — The spawning season of this species, like that of Cyprinodon variegatus, 

 continues throughout the summer. According to the records kept by Mr. Hildebrand, 

 females ripe for spawning were taken in Mullet Pond on April 17. He also observed at 

 this time that in addition to mature ova the ovaries contained immature ova in various 

 stages of development and suggested the probability that more than one brood is pro- 

 duced during the season. Young ranging from 15 to 19 mm. in length were taken on 

 May 25. During the latter half of July, when the present study was begun, this species 

 was still spawning freely, although a few of the females taken were entirely spent. The 

 ovaries of many of the females gravid with mature ova still contained immature ova 

 in more than one stage of development. Females ripe for spawning were taken in consid- 



