Biological Survey — Erie-Niagara Watershed 85 



16.5 mm. stage. Total longtli 16.5 mm; standard Icngtli 

 15.25 mm; length to vent 11.9 mm; length of head 3.5 mm; length 

 of maxillary 1.4 mm; diameter of eye 1.5 mm; greatest depth 

 (head) 2.2 mm; depth at stomach 1.9 mm; greatest depth behind 

 vent 0.82 mm. Nine dorsal elements and short rays; no anal 

 rays; caudal rays developing; small ventrals apparent directly 

 beneath dorsal rays. Vent still ending away from body at margin 

 of embryonic fin. Body somewhat heavier than preceding; pig- 

 mentation unchanofed. 



Fig. 10. — Leucichthys artedi, 17.5 millimeters 



17.5 ynm. stage. Fig 10. Total length 17.5 mm; length to vent 

 12.3 mm; length of head 3.6 mm; length of maxillary 1.4 mm; 

 greatest depth (head) 2.3 mm; diameter of eye 1.5 mm. Elements 

 complete and 10 dorsal rays visible ; 10 anal elements but no rays ; 

 ventrals larger but not rayed. 



Breeding. — The lake herring spawns in November and early 

 December, coming into shallow water in vast schools for the pur- 

 pose. The eggs incubate on the bottom during the long winter 

 months, hatching the following spring, the exact date dependent 

 upon the temperature of the water. 



Coregomis clupeafonms Mitchill — -AVhitefish 



Record of Capture. — As in the case of the lake herring, the 

 late start of our collecting trips during the past summer prevented 

 the capture of eggs and early j^oung of this species. The following 

 notes are based on a series of eggs obtained from E. L. Wickliff 

 at Put-in-Bay, Ohio, and young from 7 days to 109 days from 

 Dr. John Van Oosten, raised at the New York Aquarium. The 

 later stages described were loaned by J. L, Hart. 



Description. — Egg. Fig. 11. Diameter mostly 2.8 to 3.0 mm ; 

 perfectly spherical, yolk yellowish or amber with half its surface 

 covered by varying sized oil globules closely crowded together. 

 Immediatey after fertilization yolk entirely fills egg, with no 

 perivitelline space apparent except at one pole. At 6 hours 

 average diameter 3.0 mm, yolk diameter 2.6 mm, with widened 

 perivitelline space and the first concentration of germinal matter 

 to form the blastodisc at center of oil globule mass. Blastodisc 

 continuing to form until the beginning of cleavage at 24 hours, 



