THE FISHES OF GEORGIAN BAY 31 



SESSIONAL PAPER No. 39b 



the deep water during the summer, but is thought to migrate northwards to the 

 inshore shoals for spawning. It is an interesting fact that in the southern part 

 of the bay at least these fish do not come up on the shoals nearest their summer 

 home. The shoal whitefish is regarded as of a poorer kind, and of inferior keeping 

 qualities. The studies of the fish up to the present seem to lend some weight 

 to the opinion expressed, but it is extremely doubtful if distinct races should be 

 recognized, or indeed whether any significance should be attached to the small 

 differences appearing locally in this species. 



The following enumeration is based on 5 specimens of the shore variety or 

 run, taken in the fall. The males have the sides with longitudinal rows of weak 

 tubercles, the surface being distinctly rough to the touch. 



To facilitate comparisons with the typical specimens recently described by 

 Jordan and Evermann ('09), the measurements have been indicated in hundredths 

 of the body length. Length 18 inches. Dorsal rays 11 or 12. Anal rays 11 or 12. 

 Scales, 10, 83 to 94, 9. Gill-rakers 16 to 18. Head -20 to -22. Depth -22 to -27. 

 Caudal peduncle, length -07 to '08, depth -08. Eye, -03. Snout -05. Maxilla 



• 05 to '06. Distance from snout to occiput '14 to '16. Pectoral length -15 to 



• 18. Ventral length • 12 to • 15. Dorsal height • 14 to • 16. Anal depth • 10 to • 12. 



The following enumeration is based on 19 specimens of whitefish taken in 

 deep water (16 fathoms) off the Giant's Tomb Island. Doial rays 11 or 12. 

 Anal rays 11 to 13. Scales 10 or 11, 79 to 93, 8 (in three specimens 9). Head • 19 

 to -21. Depth .23 to -27. Caudal peduncle, length -08 to -11, depth -07 to -08. 

 Eye -03 to -04. Snout -05 to -06. Maxilla -05 to -06. Snout to occiput -13 to 

 •15. Pectoral length '14 to '16. Ventral length '12 to '14. Dorsal height 



• 13 to '15. Anal depth • 09 to -11. The gUl-rakers are 16 to 18, verified in about 

 50 specimens. 



There are several points of possible error in comparing these groups of speci- 

 mens, but taking the range of variation of the first group as a basis, we find certain 

 figures not covered by the second group, notwithstanding the large number of speci- 

 mens, and indicating for the latter group slightly shorter head, greater depth, 

 longer caudal peduncle and smaller fins. In the shape of the body the deep-water 

 fish vary from those of elliptical foim, with even dorsal profile, to those rather 

 deep and compressed, with a considerable nuchal elevation. The head appears 

 small, but not as in the Erie whitefish. 



Measurements of the head divided into the length of the body do not appear 

 to give the best results in comparing the size of the head in the different kinds 

 of whitefish, the reasons being that the characters of length of head and length 

 of body are similar or analogous. Measurements giving the proportion of head 

 length into depth of body might, however, yield dependable distinctions. A 

 rough trial of this proportion indicates for the 19 specimens above mentioned 

 a proportion of -74 to '93. By comparison, 13 specimens of C. clupeaformis 

 reported by Jordan and Evermann ('09) show roughly a proportion of -60 to '90, 

 but the exclusion of two extreme specimens from the Lake of the Woods and 

 Waubegon puts the range from • 79 to • 90. The smaller size of the head in relation 

 to the depth in C. albus, from 4 specimens reported by Jordan and Evermann, 

 is shown by the range of • 66 to • 74. 



