40 ANDBRSESON, COMPARISON OP COTTURB POROTLOPUS WITH COTTUS GORBTO. 
| 
| Fresh-water Brackish-water 
| specimens, specimens. 
10 sp.|20 sp.| AN |15 sp.]10 sp. AN 
SA 2 Ispec.ll & 9 
Distance of the first dorsal fin from | 
the tip of the anovt in 2 of the dar 
GTuANONDOdy a sn odd MN «| 28,4 | 25,9 | 28,7 | 29,1 | 29,4 |-29,2 
Distance of the second dorsal fin from 
the tip of the snout in 4 of the length 
of the body «TN VEN RM 
— 
< 
< 
-— 
- 
= 
> 
NN 
-— 
-— 
Xx 
43,9 | 44,5 
Distance betwoon tho Ist and 2nd dorsol 
fin in « of the length of the body | 15,2 | 16,81 15,61 15,8 | 15,4 | 15,0 
Longth of the base of the anal fin in 4 | 
of the distance of the first dorsal fin | 
from the tip of the snout +; .» | 76,71 TB,CV 20,01 TI,BNTSIENEEOIRN 
Length of the base of the anal fin in 4 | 
of its distance from the tip of the snout | 48 | 456 | 46 | 48,4 | 45,1 | 47,1 
Distance of the anal fin in x of the length 
| of the body. . ss si. cc or ce vs. 0 | 40,8] 47,9 | SPAN MON ER 
Height of the first dorsal fin in x of/ 
the longth of thö' body, : 0, VI 8,91 811 84) DEN 
Loast depth of the tail in x of the | 
length of the base of the anal fin. .| 20,61 26,0 | 25,9) 26,51) 26,8 | 26,4 | 
Distance between the Iateral lino and 
the second dorsol fin in « of the dis- 
tance between the lateral line and the | 
sval Är vunna fläns atv dlas IR 78,4 | 22,0 NITI,2 ] TRE 
The above table shows that the head is smaller in the 
fresh-water forms of OC. gobio than in the other forms; 80 
also is the distance from the tip of the snout to the dorsal 
lins. In the depth of the tail and in the course of the lateral 
line also the fresh-water specimens show a greater resem- 
blance to CC. poecilopus than the salt-water forms do. In 
other respects, as, for example, the development of the fins, 
one cannot detect in the fresh-water forms any greater simi- 
larity to CO. poecilopus than in the salt-water forms. 
As a final result it may be said that there exists on the 
whole in most cases a distinet difference between the species, 
that this difference does not generally appear in the diverg- 
emt directions of development, but in a development differently 
