220 
3. Dorsal Spines.—Table XI. The dorsal spines vary from 7 to 11 in Tippe- 
canoe Lake, 59.80 per cent. having nine. The variation from this number is 
almost symmetrical. In Turkey Lake the variation ranges from 7 to 10. Nine 
is the prevailing number, 52 per cent. having this number, The variation 
toward a lower number of spines is much the greater, 39 per cent. having eight, 
compared to five per cent. haying ten. The mean for Tippecanoe Lake is 9.04, 
and 8.58 for Turkey Lake. 
TABLE XI. 
| Tippecanoe Torkes Lake. 
Lake. 
Per cent. of specimens having 6 dorsal spines...|.............-[..-eeeeeeeeeee 
Per cent. of specimens having 7 dorsal spines... 1.80 4.00 
Per cent. of specimens having 8 dorsal spines... 15.40 39.00 
Per cent. of specimens having 9 dorsal spines... 59.80 52.00 
Per cent. of specimens having 10 dorsal spines. . . 22.00 5.00 
Per cent. of specimens having 11 dorsal spines. .. 1200" sl, Faca sae ee 
Mean numberof) raysso-7.s) scepter sso 9.04 8.58 
4. Dorsal Rays.—The Tippecanoe Lake specimens present a range of varia- 
tion from 11 dorsal rays to 15, The prevailing number is 13, 51.60 per cent. pos- 
sessing this number, while 38.20 per cent. have 12 and only 8 per cent. have 14. 
The Turkey Lake specimens vary from i1 to 13. The prevailing number here is 
12, 59 per cent. having this number. The variation toward a higher number is 
greater than toward a lower number. Thus, 36 per cent. have 13 and only 50 per 
cent. have 11. The mean number of rays is 12.67 for Tippecanoe Lake and 12.31 
for Turkey Lake. ; 
TABLE XII. 
| Tippeeance | Turkey Lake. 
Per cent. of specimens having 11 dorsal rays..... 2.00 5.00 
Per cent. of specimens having 12 dorsal rays..... 38.20 59.00 
Per cent. of specimens having 13 dorsal rays..... 51.60 36.00 
Per cent. of specimens having 14 dorsal rays..... 8.0090 -4)..2 rohan 
Per cent. of specimens having 15 dorsal rays..... 0.202.) |. «tins aaeanaetea 
Mean mumiber of Taya’)... cries rrr ieis ties 12.67 12.31 
