EMBRYOLOGY AND LARVAL DEVELOPMENT OF TELEOSTEAN FISHES. 429 



Larval development. — The period of incubation at laboratory temperature occupies 

 not over 18 hours. The newly hatched larvae are approximately 1.2 mm. in length and 

 exceedingly delicate. They remain highly transparent but are marked by small areas 

 of delicate yellow pigment on the dorsal aspect of the head, just over the vent, and in a 

 vertical band approximately halfway from the vent to the tip of the tail. Both dorsal 

 and ventral fin folds are continuous. The depth of each fold is equal to or greater than 

 the depth of the body posterior to the vent. The vent is located a little less than half 

 the length of the body from the anterior end. 



These larvae being extremely delicate, it was not found possible to keep them 

 alive in the laboratory longer than a few hours. As no recently hatched young were 

 taken, the advanced larval stages can not be described. Young ranging from 25 to 30 

 mm. in length have already assumed the general appearance of the adults and present 

 many of the diagnostic characters of the species. 



97867°— vol 34—16 28 



