SALMONIDJE. 
875 
Genus MALLOTUS'. 
No canines; small , fine teeth , hardly distinguishable to the naked eye, set in one row in the anterior part of the 
lower jaw , on the inter maxillaries, the maxillaries, the head of the vomer, the anterior extremity of the palatines, 
the mesopterygoid bones, and the tongue. Length of the maxillaries as a rule 57 b — 63 %, and, that of the lower 
jaw as a rule 7 5 C — 90 %, of the length of the head reduced. Number of rays in the anal fin 20 — 24, 17 d — 20 
being branched; and the base of the anal fin longer than that of the dorsal. C cecal diverticula at the pylorus 
short and few ( about 4 — 6). Scales smalt, about 200 in a row along the sides of the body, and the lateral line 
complete, at least to the perpendicular from the end of the anal fin. 
Between Mallotus and Osmerus stands the Arctic 
American Eulachon (Thaleichthys pact ficus), with scales 
only slightly smaller than those of the Smelt and den- 
tition feeble as in the Capelin C Thus we cannot ex- 
pect to trace the descent of the Capelin immediately 
from the Smelt or the reverse. In several respects, it 
is true, we find that the Smelts represent an earlier 
stage of development, more nearly approximated to the 
presumable original form. One of the most prominent 
differences between the two genera lies, for example, j 
in the shape of the anal fin, the height of which is 
always more in the Smelts, less in the Capelins, than 
half its base. Now in the former 7 we find in the aver- 
ages a difference both of age — the young have a rela- 
tively higher anal fin than the old — and of sex — the 
females have a relatively higher anal fin than the 
males — both of which relations point to the transition 
from Osmerus to Mallotus. In most other respects, 
however, Mallotus comes nearer to the original form, 
such as we may assume this form to have been, jud- 
ging by the manner in which the characters appear. 
Thus, for example, Mallotus has a narrower snout than 
Osmerus , the breadth of the snout across the articular 
knobs of the maxillaries being less in Mallotus, more 
in Osmerus, than 1 /' 4 of the length of the head or 1 / 3 
of the length of the head reduced. In Mallotus as in 
Osm. eperlanus the percentages for these relations also 
rise with increasing age. The sexual distinction is, 
however, different here: in the Capelins (as in Osm. 
dentex and Osm. spirinchus ) the snout is as a rule 
narrowest in the females, in Osm. eperlanus in the 
males. Another character wherein Mallotus also repre- 
sents a lower grade of development, may be found in 
its adipose fin, which is of uniform height, long and 
low, and which, like the embryonic fins that we have 
remarked in several preceding genera, is furnished 
with a countless number of fine supporting fibrils. 
The feeble dentition approximates Mallotus more close- 
ly to the following subdivision of the Salmonoid 
family, although the immediate transition from Osme- 
rus to the said subdivision passes through other 
genera, as for instance Nelma ( Stenodus ) and Hypo- 
mesas. 
Only one species of the genus is known C 
a 
a Greek gaXXcoxoq = Lat. 
6 In exceptional cases 55. 
villosus, 
hairy. 
e Eulaclion is besides remarkable for its fatness. In a dried form it is a food of good flavour and, when lit. burns like a lamp. 
f Most distinctly, judging by the Royal Museum specimens, in Osmerus dentex and Osm. spirinchus. 
rj The difference given in Rilcsmuseets Salmonider between the Capelins of the Old and New Worlds has proved, on examination of 
greater number of specimens from Greenland, to be untenable. 
