708 
SCANDINAVIAN FISHES. 
mouth and belong to the thick part of the lip. On the 
lower jaw too, the lip runs back in a dermal flap on 
each side. This flap, as Kroyer 3 has already pointed 
out, may now and then be denticulated or even pro- 
duced at some spot so as to resemble a barbel, thus 
depriving the above-mentioned generic difference be- 
tween Cobitis and Misgurnus to some extent of its 
validity. The intermaxillary bones are small and nar- 
row, with the main branches only slightly longer than 
the straight nasal processes. The maxillaries, on the 
other hand, are high and of singular form. Behind the 
articular knob they expand into a square, but again 
contract, and at the hind extremity once more expand 
into a rounded lobe curved in a downward direction. 
In the upper jaw we find a well-developed palatal fold. 
There is no free tongue. On the first branchial arch 
the gill-rakers are set in a single row (containing 11 — 
14) corresponding to the posterior row on the other 
Fig. 177. Right lower pharyngeal of a Cobitis taenia , seen from 
within and above. About 15 times the natural size. 
arches, where they are set in a double row, and on the 
lower pharyngeals in one row (containing 7) on the outer 
anterior margin of these bones. They are short and 
depressed. The pharyngeal teeth are subulate, pointed, 
and curved; they are set in a row (10 or a few more, 
3 of which lie on the upper arm) on the inner (posterior) 
margin of the lower pharyngeals, which are geniculate, 
like branchial arches. Sometimes, however, we find one 
or two smaller teeth (supplementary teeth?) beside the 
principal row. The gill-openings are merely vertical 
slits, the branchiostegal membrane on each side of the 
body coalescing with the skin at the anterior end of 
the insertion of the pectoral fin. The height of the 
opening is about equal to the thickness of the head at 
the eyes; but the branchiostegal membrane is loose, the 
gill-openings being thus capable of expansion by means 
of the three long, sabre-like branchiostegal rays on each 
side. The preoperculum extremely narrow, the other 
opercular bones well-developed. The hind inferior 
margin of the operculum proper is curved in an S-shape, 
with the anterior lower corner produced in a downward 
direction, but the breaks are filled by the suboperculum. 
As we have mentioned above, the head is scaleless; but 
the ducts belonging to the system of the lateral line 
are usually quite distinct on its surface, being marked 
by rows of small pores, often raised in a tubular form, 
along the temples, straight across the occiput, along the 
preoperculum and the branches of the lower jaw, on 
the forehead and at the upper orbital margin on each 
side, and along each of the cheeks, below the slit con- 
taining the preorbital spine and forward on the snout 
below the nostrils. 
The body, on the other hand, is densely covered 
with small, round, thin, imbricated, cycloid scales. The 
lateral line is distinct only at the very beginning, where 
it forms a backward continuation of the temporal canal, 
first sloping downwards and then straight, for a distance 
of about twice the longitudinal diameter of the eyes. 
The dorsal fin is obliquely rectangular, with the 
upper angles rounded, the upper posterior margin being 
thus more or less convex. Its base is somewhat elevated 
in front, forming a slight break in the otherwise straight 
contour of the back. Its beginning lies at a distance 
from the tip of the snout that measures about 41 — 43 
% of the entire length of the body, 47 — 50 % of the 
length of the body minus the caudal fin, or 67 — 65 % 
of the distance between the anal fin and the tip of the 
snout, and is generally situated somewhat in front of 
the perpendicular from the insertions of the ventral fins. 
At its origin we find two rudimentary, unarticulated 
rays (supporting rays), the first extremely small, the 
second about one-third as long as the third ray. The 
third ray is simple (undivided) but articulated, and 
only slightly shorter than the fourth, which is the 
longest ray in the fin and, like the remaining rays, 
branched. The last ray is about half as long as the 
longest one, and there is no fin-membrane behind it. 
The shape of the fin is highly inconstant, the length 
of its base (on an average about 87 2 % of the length of 
the body 6 ) varying between 64 and 76 % of its height 
(the length of the longest ray). 
The anal fin is of the same structure and shape as 
the dorsal, only that the branched rays are fewer and 
a Damn. Fislce, III, p. 568. 
b Varying, according to Canestrini’s measurements, between 7‘2 and 10 % of the length of the body. 
