420 



BULLETIN OP THE BUREAU OE FISHERIES. 



cytoplasm. This conclusion is in full accord with the findings of Franz (1908) in lar\'ae 

 of Pleuronecies plaiessa." 



As development advances ameboid movements of the chromatophores become 

 less apparent. No conclusive evidence of ameboid movement of chromatophores was 

 secured during the later stages of embryonic development or in newly hatched fishes. 



Larval development. — The newly hatched larvse are 4.5 to 5 mm. in length. The 

 yolk sac remains large but the head is not deflected. The dorsal fin fold has its origin 

 relatively far posteriorly. Both dorsal and ventral fin folds are continuous. The 

 depth of each fold does not exceed half the depth of the body posterior to the vent. 

 The vent is located at the posterior margin of the yolk sac. The color is light yellow 

 and quite uniform. 



At seven days after hatching (fig. 31) the larvae have grown to a length of approxi- 

 mately 6 mm. The yolk is completely absorbed. The head is slightly depressed and 



Fig. 30. — Newly hatched fish, actual length 4.5 mm. 



Fig. 31. — Larval fish 7 days after hatching, actual length 6 nun. 



LUCANIA PARVA. 



the depth of the body is somewhat greater than in the preceding stage. The color 

 remains light yellow. 



The young of this species assume the general appearance of the adults relatively 

 early. Young 15 to 20 mm. in length show many of the diagnostic characters of the 

 species. The larger young taken in July and August were almost identical in appear- 

 ance with the adults. 



KIRTLANDIA VAGRANS. ROUGH SILVERSIDE. 



Spawning. — During the latter half of July and the first week in August a few females 

 of this species ripe for spawning were brought into the laboratory. The great majority 

 of the females taken during this period were already spent. The height of the spawning 

 season obviously occurs earlier in the summer. 



Eggs. — The mature unfertilized ova are spherical in form and 0.8 to i mm. in diame- 

 ter. They are slightly heavier than sea water and are held together in clumps by a 

 tangle of adhesive threads, a small tuft of which arises from the membrane of each egg. 

 They are slightly yellowish in color and almost transparent. A small perivitelline 



a Franz, v.: Die Stniktur der Pigmentzelle. Biologisches Zentralblatt, vol. 28, p. 536-543. 



