88 



Conservation Department 



ish. Cliroiiiatopliores same in number and arrangement but size 

 increased until they overlap in marginal series. 



Fig. 15. — Coregonus clupeaformis postlarva, 18.5 millimeters 



18.5 mm. stage. Fig. 15. Age unknown but similar to specimens 

 61 days old. Total length 18.5 mm; standard length 17.0 mm; 

 length to vent 13.25 mm; length of head 4.0 mm; depth of head 

 2.25 mm ; greatest depth behind head 2.0 mm ; diameter of qyq 

 1.6 mm. Dorsal rays fairly well developed; embryonic marginal 

 starting again after wide space behind dorsal, continuing to caudal, 

 complete on ventral side, with basal elements of anal fin developed 

 but no rays; caudal slightly notched dorsally at end of notochord, 

 lower portion becoming forked and rays well formed; ventrals 

 prominent. Dorsal and ventral series of chromatophores still 

 important but many smaller ones scattered over sides of head, 

 body and caudal. 



22.0 mm. stage. 65 days old. All fins fully developed with 

 exception of adipose, in which region a large fragment of the 

 embryonic marginal remains. 



Fig. 16. — Coregonus clupenjormis young fish, 31.5 millimeters 



31.5 mm. stage. Fig. 16. Age unknown but similar to speci- 

 mens 95 to 109 days old. Total length 31.5 mm; standard length 

 27.0 mm ; length of head 6.75 mm ; greatest depth of body 4.5 mm ; 

 diameter of eye 2.0 mm. Assuming shape of adult. Pigmenta- 

 tion essentially as in younger specimens but more diffused with 

 dorsal and ventral ridges of body from head to caudal still most 

 deeply pigmented ; black, stellate dorsal chromatophores continu- 

 ing down the sides to lateral line becoming gradually smaller and 

 wider apart; lateral line marked by closely distributed small 

 black si)ots; few chromatophores on ventral aspect of stomach 

 but none beneath intestine ; large areas of chromatophores behind 

 eye still noticeable, and many more, lighter in color, between and 

 befoi'c Ihc eves Ix'comin"- darker at mouth: dorsal and caudal 



