BIHANG TILL K. SV. VET.-AKAD. HANDL. BAND 24. AFD. IV. N:0 9. 9 
32,4, 33,3 and 31,9 2, in four smaller specimens measuring 
resp. 54, 50, 36 and 35 mm. the same percentage is 29,e, 29,0, 
32,0 and 28,5 2». Thus it varies a good deal but seems to be 
larger in the adult females than in the males. The length 
of the base of the second dorsal fin ought to be less than 
27 2 of the total length in OC. uncinatus, but more than 28 4 
in C. hamatus according to Smitt. In OC. uncinatus I have 
found this percentage to vary from 21,1 2 to 26,2 2». In C. 
hamatus the three male specimens mentioned above showed 
this relation to be resp. 28,4, 28,2 and 29. One of the females 
(tot. length 69 mm.) had the percentage 29,0, but in the two 
others it was remarkably low namely 26,6 and 24,6 2. Fe- 
males and young specimens of C. hamatus are then in this 
respect more similar to C. uncinatus than the males are. 
Another comparative characteristic pointed out by SMITT is 
that in OC. uncinatus the length of the base of the anal fin 
is at least 80 x of the length of the base of the second dor- 
sal fin, but in C. hamatus less than 72 Z. This is however 
subject to great variation as in 4 C. uncinatus I found resp. 
97,2, 73,3, 87,5 and 90,1 and in the 3 male C. hamatus: 10,2, 
61,1 and 72,2, in the 3 female: 84,2 (the second dorsal very 
short!), 75,0 and 70,0. In this case also the females of C. 
hamatus come nearer to OC. uncinatus. "The great variations 
with regard to the comparative measurements of the anal 
and second dorsal fins are due to the variation of the number 
of rays in these fins, as for instance, in the case where the 
mentioned percentage in a C. uncinatus only was 73,3 the 
anal had only 10 rays and the second dorsal 14 rays. The 
distance between the ventral and anal fins is, as a rule, a 
little larger in C. uncinatus than in C. hamatus, especially 
is this difference pronounced in the female specimens. 
LÖTKEN ! regards CO. uncinatus as an inhabitant of deep 
water. The specimens dredged by the Swedish Expedition 
1898 were also found in no less depth than 80 fathoms (off 
Grey Hook) and in other instances still deeper down to 
410 m. It is an arctic species distributed from Greenland 
to the neighbourhood of Behrings Sound. It was however 
hitherto not known from any more northerly locality than 
Lat. 75 31' N. and CoLLEtt? considers it to have a compara- 
