1895.] Leuciscus Balteatus, A Study in Variation. 15 
TABLE OF VARIATION FOR 18 SPECIMENS FROM THE COLUMBIA AT GOLDEN. 
y | = | | | | i 
No. tenet ae Anal.| | Seales. | Teeth. | Depth. | Head ofãorsal. Sex Remarks. 
oer hike 
mm. | | | | 
1 115 | 12% | 414; (* Keel nil. 
2} 104 | 11% | latg] o a? $ | Keel evident. 
3 103 | 11% t 1-4 | * Q] Do. 
4 103 | 11% 4 2-7 (s g Do. 
5 95 | 12% | (41-3) (tł Q | Keel well marked. 
6 92 | 11% 4 1-4 (2 ? | Keel well developed. 
7 91. | 12% | 4 1-5 (Doo bea | Keel nil. 
8 85 | 11%/1 41-5) be hares perce Keel well developed. 
9 85 | 12% FEDI A Ee Keel scarcely evident. 
10 82 | 11% (41-4 I afisk Keel evident. 
11 83 | 11% | oe tey: pa 
12 TAU 141-4 EETRI ee Keel evident. 
13 W E E oaa auaa E >” ferda (t) |... Keel well developed. 
14 72 | 10% $a pe eee | Keel moderate. 
15 68 | 11% bd Ree Bes Keel well developed. 
16 67 | 12% e tee | 0. 
17 65 | 12% | eb Wiis Ps | Keel strong. 
18 OR T kr el a Pee ed Do. 
* pa from = of oe y Staw op eee ag of scaled region). 
rsal nearer base of middle 
t Equidistant from aad of middle ma rays and upper 
ĝ Equidistant from base of middle caudal rays and estar yy margin ofe eye. 
in the anal is enormous, but this I shall treat in detail. The 
scales are seen to vary from 10 to 14 above the lateral line; 
from 55 to 63 along the lateral line, and from 5 to 7 below the 
lateral line. There is nothing unusual in these variations, 
they are surpassed or equalled by other members of the same 
family. The variation in the teeth is great. With one excep- 
tion, there are two teeth in the lesser row of the left side. The 
major row on the left side contains 4 or 5 teeth in the propor- 
tion of 1 to 6. In the right side, 3, 4 and 5 teeth were found 
in 4,30, and 2 specimens respectively. In the lesser row of 
the right side, 13 specimens had 1 tooth, 20 had 2 teeth and 
one had 3. This last specimen, with dental formula 2,5-5,3, 
exceeds the dental formula of all the 175 Atlantic slope 
species of this family. Among these dental formule we 
find variations, the extremes of which have been taken as 
generic characters in other members of the Cyprinide. 
The different combinations of teeth and the number of speci- 
mens having each number are as follows: One with 1,5-4,1 ; 
-one with 1,5-4,2 ; two with 2,4-3,1; one with 2,4-3,2; one with 
2,4-4,2 ; one with 2,4-5,2 ; one with 2,5-3,2 ; eleven with 2,5—4,1; 
sixteen with 2,5-4,2; one with 2,5-5,3. The usual or normal 
