Translation 2783

:.... 1-73
The lower jaw is convex and extends beyond,• the end of the snout:
';Then the IROuth is closed the flat upper ja;•r is colapletely en'sttlfed
by the ou'ttaarcll.^ -bul^in; lot`ler jaw (there are no lil,s, -as such
forming a straight lizie with an abrupt curvature of the mouth belo^r
the. eyes. The baleen plates are joinect.toge tner at tue end of tue
snout -by a f;rou,) of small rods of horny mraterial. E ach row may conts.â.n
uir to 450-11.75 baleen plates, from 20 or 21) c:a to 100 cln lorlg,.
x`c>,r.o7.y lona'er. 11'he width of 1;VEese plates is up to 30,.. of tileir
leng,th, The oral cn.vity is low, but wide, a, lare part of it beinE;
occurried by the extre;lely-movabl.e toniSue.
In most rorquals the flippers are lancet-like and narrow, with
four digits. The flukes are broad, with c.^ conspicuous indentation
in the middle. The spout corisists of a single jet.
On tiie basis of the biological rhythms, whicii are opposite in
season, and of differences in the sizes of ;lpecim.er'ls of the same age
^in slrite of the absence of observable morpholog].ec,l difi'e,.:•ences), _
it is considered that independent .(;•eoC;ra^;hicnl races ^subspecies)
exist in the two hemispheres. 'Southerl'1 speciilen.> are larLn,-er.
4
The family contains two genera: hump-back whalcs (t,rith a single
species) and 'true rorquals ^five species).
.
C,erlu,s Pic-.,Lera CTr^t,y, 1846 ^;iump-ba.ck l.;hales)
hump-back ',lhe.le nodosa•;