NAVAGA AND WACHNJA. 
483 
Average in 
4 specimens 
of navaga 
from 
Archangel. 
3 specimens 
of wachnja 
from 
Pitlekaj. 
Longitudinal diameter of the eves in % of the length of the body 
3.5 
3.6 
Least breadth of the interorbital space „ „ ,, ,, „ ,, ,, ,, 
5.7 
<).l 
Length of the snout ,, „ „ 
7.7 
7.4 
Distance between the first dorsal tin and the tip) of the snout ,, ,, ,, ,, „ 
29.7 
30. c 
„ ,, ,, second ,, ,, ,, „ ,, „ „ ,, ,, „ ,, 
42.2 
43.3 
,, „ „ third „ „ „ „ „ „ „ „ „ „ „ ,, „ ,, ,, 
64. s 
65.2 
,, „ ,, first anal „ ,, ,, ,, ,, ,, ,, .. ,, ,, ,, ,, , 
43.5 
43.i 
Length of the base of the first dorsal fin , ,, .. ,, ,, 
10. o 
10.3 
,, ,, „ ,, „ ,, second „ ,, „ ,, „ „ ,, ,, 
17.2 
16. « 
„ „ ,, ,, „ „ first anal ,, ,, ,, ,, „ „ „ 
19.9 
18.7 
,, „ „ ,, „ second „ „ „ „ .. „ „ 
14.7 
14.5 
,, ,, longest rav in the first dorsal fin , .. „ ,, „ ,, 
10.3 
11.0 
„ „ ,, „ ,, „ „ second ,, „ ,, „ „ ,, „ 
9.5 
9.6 
„ „ „ „ „ „ „ third „ „ „ ,, „ „ ,, ,, „ 
9.2 
9.i 
,, „ „ ,, „ „ first anal ,, ,, .. ,, 
9.1 
9.4 
,, ,, ,, ,, ,, ,, ,, second „ ,, ,, ,, ,, ,, .. 
8.2 
8.9 
.. pectoral fins „ ,, „ ,, ,, „ 
13.i 
13.7 
ventral .. 
11.4 
11.4 
Distance between the ventral fins and the beginning of the anal fin. , ,, „ ,, „ „ ,, 
25.4 
23.6 
Length of the middle caudal rays - „ „ ,, ,, „ „ „ 
6.4 
6.8 
We thus find on an average that in wcichnja the 
breadth of the forehead is comparatively greater than 
in navaga , just as it is greater in Gad as ogac than in 
the Common Cod; while, on the other hand, the distance 
between the ventral tins and the beginning of the anal 
fin, contrary to the tendency of the changes of deve- 
lopment and in contradistinction to the relation between 
Gadus ogac and the Cod, is on an average less in 
wachnja than in navaga. Only the first six of the re- 
lations given in this table, however, show any constant 
difference of character. The maximum and minimum 
proportions also show that these differences, with the 
exception perhaps of the sixth, are difficult to employ 
in the limitation of the species. Better results are 
obtained in the following table, which is also calculated 
to give an expression for the tendency of the changes 
of growth. This table is based on an examination of 
twelve specimens, six of Gad as navaga , between 171 
and 240 mm. long, and six of G. gracilis , between 
about" 208 and 382 mm. in length. 
Average in 
Navaga. 
Wachnja. 
3 specimens. 
8 specimens. 
3 specimens. 
3 specimens. 
Length of the body expressed in millimetres 
192.3 
227? 
242? 
358 
,, ,, „ head ., ,, ,, 
42.8 
50.3 
53.7 
79.6 
Length of the snout in % of the length of the head behind the eves h 
68.7 
70.7 
64.8 
63.o 
Least depth of the tail in % of the length of the lower jaw V 
35.8 
38.7 
42.3 
43.3 
?? ?? ii ii ii ii ii ii ii ii ii snout 
47.c 
49.6 
56.8 
56.9 
breadth of the interorbital space in % of the lenglh of the snout' 
75.i 
73.7 
86.3 
82.7 
„ ,, „ „ „ „ ., „ „ „ „ ,, „ head-^ 
25.7 
25.5 
27.9 
27. g 
a The body is so distorted in the smallest specimens that its length cannot be fixed exactly. 
6 Minimum in navaga = 68’2 %, maximum = 72*1 %. 
Maximum ,, wachnja = 65'5 %, minimum = G1.8 /. 
c Maximum ,, navaga — 39" 1 /, minimum = 34\3 %. 
Minimum ,, wachnja = 4 1 ' 1 %, maximum = 45'4 %. 
d Maximum ,, navaga = 50 °/o, minimum = 461 f. 
Minimum ,, wachnja = 52’6 %, maximum = 60 %. 
e Maximum ,, navaga = 7 8 ' 1 %, minimum = 69'4 %. 
Minimum ,, wachnja == 80 %, maximum = 8 8 ‘ 8 %. 
f Maximum ,, navaga = 26‘4 °/i, minimum = 24 %. 
Minimum ,, wachnja = 26.7 /, maximum = 28'9 %. 
