8 ANDERSSON, COMPARISON OF COTTUS POECILOPUS WITH COTTUS GOBIO. 
saying that in this species, more at least than in other Cotti, 
the rays in the pectoral and ventral fins show a tendency to 
divide at the point, which is visible only under a magni- 
fying glass: to the naked eye the rays seem simple. Pro- 
fessor LILLJEBORG pronounces all the rays to be simple, and 
in the second edition of »Scandinavian Fishes» we find a si- 
milar statement to the one first given. 
On examining in this respect more than a hundred spe- 
cimens of C. gobio from different parts of Sweden, I found 
only three specimens that had the rays branched in the ven- 
tral fins and they had also branched rays in the pectorals. 
One of these specimens from the islandbelt outside Stockholm 
had the three lower' soft rays in the ventrals and the two 
middle ones in the pectorals bifid, another from the same 
place had the second lower soft ray in the ventrals bifid 
and likewise two rays in the left and three in the right pec- 
toral fin, and the third specimen (an old Linnean) had the 
three lowest soft rays bifid in one of the ventrals and like- 
wise the two lowest in the other; and, in the pectoral fins, 
7 rays in one and 4 in the other were bifid. — The definite 
statement mentioned above as given by ARTEDI with regard 
to the branching of the ventral rays seems to us very sin- 
gular, as he evidently was not limited in his examination 
to one single specimen, which might have happened to be an 
exceptional case. With regard to the pectoral fins he de- 
clares the rays to be simple, excepting in some specimens, 
which are found to have 2 or 3 branched rays. In our Swe- 
dish specimens, however, it is clear that it is only excep- 
tionally that we find the rays branched in the ventral and 
pectoral fins, for which reason we cannot regard them as in 
this respect characteristic of Sweden. As to the above- 
mentioned French local form, which Dar pronounces to have 
branched rays only in the pectoral fins, it is proved by BLAN- 
CHARD to be in this respect exceedingly variable, as the rays 
are sometimes found simple, sometimes branched. The same 
variations seem to exist also in Austria, according to HEcKEL, 
and sometimes also in England, as appears from a statement 
made by GIRARD, and mentioned in Day's »The Fishes of Gr. 
Brit. & Ireland». In this respect, however, it is evident that 
the forms vary in a similar manner in different places; but 
it seems as if the tendency to branching of which EKSTRÖM 
