864 
SCANDINAVIAN FISHES. 
least a trace of canine formation; but the maxillary 
teeth are still smaller, set closer together, at least in 
places, and rather blunt. The tongue is boat-shaped, 
with fleshy lateral margins and bears at the tip one or 
two large canines and on each side of the true hyoid 
bone (os linguale), within the said margins, a row of 
somewhat smaller, similar teeth or only one or two, 
in the latter case large canines. The copular part of 
the hyoid bone is armed with smaller teeth, of about 
the same size as the intermaxillary teeth, the largest 
in a row along each of the edges, the others (the inner 
ones) irregularly distributed in two rows. The pharyn- 
geal teeth are about equal in size to those on the co- 
pular part. Among the upper pharyngeals of the Scan- 
dinavian Smelt only the two hind pairs are furnished 
with teeth, the hindmost with several (3 — 4) rows, 
the penultimate with one row. On the elongated lower 
pharyngeals the teeth are set in two rows. These 
numerous teeth of different form show that the Smelt, 
in proportion to its size, is a voracious fish-of-prey. 
The intestinal canal is short. The oesophagus 
with its longitudinal inner folds passes uniformly into 
the thick-walled stomach, which resembles a caacum, 
and the bottom of which sometimes does not even 
extend to a line with the tips of the pectoral tins, but 
sometimes reaches to the anterior extremity of the 
pelvic bones. On its under surface and in about a 
line with the middle of the pectoral fins, the pyloric 
part originates, running forwards at an acute angle, 
and extending almost to the diaphragm, where it bends 
abruptly back at the transition to the intestine, which 
is here furnished with a few" comparatively short, but 
thick pyloric appendages. The intestine runs straight 
back to the vent. The liver is short and lies almost 
entirely to the left of the oesophagus and stomach; it 
extends back to about a line with the pyloric angle. 
On the right, between the oesophagus and the small 
lobe which the liver sends out on this side, lie the 
gall-bladder and, a little further back, the spleen, which 
in a healthy state is very dark, nearly black, and 
ellipsoidal, more or less flattened * 6 . In the structure 
of the generative organs we have above remarked a 
peculiarity characteristic of the Smelts: behind the 
ovaries or, when they are fully ripe (in the spawning- 
season), beside their posterior part, the mesoarium joins 
its ventral margin, which in the preceding genus hangs 
free in the abdominal cavity, to the lateral wall of the 
said cavity, thus forming an oviduct open in front 
(fig. 208, p. 828). The left ovary is the larger and 
lies more to the front. In the spawning-season it 
occupies almost the whole length of the abdominal 
cavity, all the way from the diaphragm. The right 
ovary lies in the posterior part of the abdominal ca- 
vity, and extends forward only a little beyond the in- 
sertion of the ventral fins. The testes occupy the same 
position with relation to each other, and the left testis 
is also the larger; but the difference in their size is 
not so great as in the case of the ovaries. The air- 
bladder is simple, long, and united throughout its length 
to the dorsal side of the abdominal cavity, but does 
not extend forward to the diaphragm or back quite to 
the end of the cavity. From the lower part of its 
anterior extremity the pneumatic duct runs to the 
oesophagus. 
The skull is weakly ossified, more elongated and 
shallower than in the Salmons, and without the cur- 
vature characteristic of the latter in the sphenoid re- 
gion. Nor does the parasphenoid bone extend so far 
back as in the preceding genus: its hind extremity 
lies outside (under) the front portion of the basilar 
part of the occipital bone, which part behind this point 
is tumid on each side, whereas the Salmons here have 
only a longitudinal, terete carina. This swelling, the 
anterior part of which belongs to the temporal region, 
includes the sacculus of the labyrinth, with the flat, 
but long, heart-shaped otolith, which in a Smelt mea- 
suring 177 mm. is 5 mm. long. The posterior oculo- 
muscular canal extends about as far back as the para- 
sphenoid bone, and thus belongs to the sphenoid and 
temporal regions. The basisphenoid bone is wanting, 
and the wall between the orbits is reduced to a car- 
tilaginous ridge, ascending in front and belonging to 
the hind part of the ethmoidal cartilage. The maxil- 
laries with their os supplement are {jugate), the inter- 
maxillaries, the palatines, the vomer, and the pterygoid 
bones, are arranged as in the Salmons; but the reduc- 
tion of the vomer and the dentition of the mesopte- 
rygoid bones we have already noticed. The bran- 
0 According to Keoyeb 3, to Day sometimes as many as 7 ; we have most often found 5 . 
6 In a male Smelt 133 mm. long the spleen was G mm. long during the spawning-season, in two females measuring 139 and 177 
mm. the spleen was respectively 5 and 7'8 mm. in length. 
