BIHANG TILL K. SV. VET.-AKAD. HANDL. BAND 24. APD. IV. N:0 8. 41 
advanced in the same course. The differences between the 
two forms thus observed are as yet slightly marked, being 
often overstepped on either side, that no constant limits can 
be set, distinguishing the two species. 
Except in those respects in which there is certainly a 
divergent course of development, the greatest difference be- 
tween the species is to be found in the different development 
of the anterior part of the body and of the unpaired fins. 
'These characters are also employed by Professor SMITT as a 
distinetion between the species in comparing the length of 
the anal fin with its distance from the tip of the snout. As 
has been stated above, there was no constant character to be 
detected in this measurement, and I arrived at the same 
conclusion, making similar comparison with other measure- 
ments. Comparing, for instance, the length of the base of 
the anal fin with the distance from the first dorsal fin 
to the tip of the snout, we obtain, according to my mea- 
surements, the following table of averages, whieh seems to 
show that a fairly considerable difference exists between the 
forms, 
CU. poccilopus, 0. gobio, 
A KN Ol NOR DÅ OK KY IN 
E I SV 45,21 50,5) 20,1) 42,5) 67,0) 70,5 
Length of the body in millimetron . | 7; f SE e va 
19 | 48.4] 62,7) 70,11 42,41 58 |) 75,8 
Length of the base of the anal fin in w« of | 
the distance between the tip of the snout IS 94.8 
An MA 
NL VAS 180 Dt RV I MALD HA. DIA GE, då | 
0 
— 
fm | 
jos 
78,8 
Q | 95,31 93,41 92,21) 74,4 70,5) 74,4 
Carefully examining the different measurements, we find 
here in this respect also some specimens which indicate a 
transition between the different branches, Thus the five 
highest measurements in OC. gobio are: 89-—84,4—83,8-— 85,3 
82,2; the five lowest in C. poecilopus are 79,1—84,4-—85,1— 
56,2—86,8. i 
Comparing the length of the anterior part of the head 
with the distance from the first to the second dorsal fin, which 
distance is nearly equal to that of the base of the first dorsal 
lin, we obtain the following table of averages. 
