Spor af tandformige Fremspring. Foruden de kraf- 
tige Adductormuskler, der fylder Storsteparten af 
den indre Hulhed af Corpus, sees ogsaa en Del 
andre Muskler at passere til Kindbakkerne, ved 
Hjelp af hvilke disse kan dreies om sin Axe inden 
visse Grendser. De sterkeste af disse Rotations- 
muskler udspringer fra den dorsale Flade af Nakke- 
segmentet og convergerer mod Kindbakkernes bagre 
Side (se Fig. 2). Nogle betydelig mindre Muskler 
passerer fra Hovedets dorsale Integument til For- 
siden af Kindbakkerne. 
Nogen Underlebe har det ikke lykkets mig at 
paavise. Prof. Lilljeborg tror dog at have fundet 
den i Form af 2 meget smaa tilspidsede og tet haa- 
rede Lappe. 
Forste Par Kjever (Fig. 2, 4, 9, m', Fig. 10) 
bestaar af en kort og tyk Basaldel og en meget 
beveegelig indadboiet, skiveformig Endedel, der paa 
sin frie Rand er besat med en tet Rad af tynde, 
leformigt krummede Borster, alle tydeligt 2-leddede 
og fint cilierede. Foruden dem findes der endnu en 
Rad af betydelig kortere Borster eller Pigge, der er 
grovt tandede i Kanterne og ender i en serdeles fin 
og delicat Spids (se Fig. 11). Disse Borster er dog 
kun indskrenkede til den bagre Halvdel af Randen. 
Endelig bemerkes fortil, i Vinkelen mellem Basal- ~ 
delen og Endelamellen en meget liden, men tydeligt 
begreendset, secunder Lamelle af smal tungedannet 
Form og kantet med nogle ganske korte Borster. 
Andet Par Kjever (Fig. 2, 4,9, m?, Fig. 12, 13) 
er betydelig mindre end 1ste Par og, som det synes, 
kun lidet bevegelige. De bestaar ligeledes af en 
kort Basaldel og en indadrettet Endelamelle af 
elliptisk Form, med det indre afrundede Hjorne be- 
tydelig mere fremspringende end det ydre. Lamellen 
er kantet med omkring 24 tet cilierede Borster, som 
dog er utydeligt leddede og kun mod det indre 
Hjorne naar nogen betydelig Lengde. 
Af Fodder har jeg hos fuldt udviklede Individer 
talt 22—23 Par. Prof. Lilljeborg har hos ualmin- 
delig store Exemplarer endnu fundet et Par bag 
disse, saa at deres Tal kan stige til 24 Par ialt; ja 
Grube paastaar endog hos et Individ at have talt 
26 Par. De er idethele af en meget uniform Byg- 
uing og viser alle Characteren af egte Branchial- 
fodder. Foruden til Respiration, har de imidlertid 
ogsaa en veesentlig Betydning ved Neringsoptagel- 
sen, idet de i Vandet verende organiske Smaadele, 
hvoraf Dyret nerer sig, ved Foddernes rhytmiske 
Bevegelser bliver hvirvlet ind mod Munddelene. 
De 10 eller 11 forreste Par er nogenlunde af samme 
Lengde, men fra det 11te Par begynder de steerkt 
at aftage i Storrelse, og de allerbagerste Par er 
overmaade smaa og vanskelig at telle. De har alle 
93 
broad, finely-fluted molar surface without a trace of 
dentate projections. Besides the powerful adductor 
muscles, which fill the greater part of the inner 
cavity of the body, a few other muscles are also 
seen passing to the mandibles, which, by their aid, 
ean turn upon their axis within certain limits. The 
strongest of these rotatory muscles issue from the 
dorsal surface of the cervical segment, and converge 
towards the posterior side of the mandibles (see 
fig. 2). Some much smaller muscles pass from the 
dorsal integument of the head to the anterior side 
of the mandibles. 
I have not succeeded in proving the presence 
of any posterior lip. Prof. Lilljeborg, however, be- 
lieves that he has found it in the shape of two very 
small, pointed, and densely hairy lobes. 
The first pair of maxille (figs. 2, 4, 9, m', fig. 
10) consist of a short and thick basal part, and a 
very movable, incurved, lamellar, terminal part, 
which is clothed on its free margin with a close 
row of thin, falciformly curved bristles, all distinctly 
2-jointed and finely ciliated. In addition to these, 
there is yet another row of much shorter bristles 
or spines, which are coarsely dentated at the edges, 
and end in a particularly fine and delicate point 
(see fig. 11). These bristles, however, are only con- 
fined to the posterior half of the margin. Lastly, 
there is visible in front, in the angle between the 
basal part and the terminal lamella, a very small, 
but distinctly defined lamella, of a narrow lingular 
form, and edged with a few very short bristles. 
The 2nd pair of maxille (figs. 2, 4, 9, m?, figs. 
12, 13) are considerably smaller than the first pair, 
and apparently only slightly movable. They also 
consist of a short basal part, and an inward-direc- 
ted terminal lamella of elliptical shape, with the 
inner rounded corner considerably more prominent 
than the outer one. The lamella is bordered with 
about 24 thickly ciliated bristles, which are how- 
ever, indistinctly articulated, and only at the inner 
corner attain any considerable length. 
In fully developed animals, I have ented from 
22 to 23 pairs of legs. Prof. Lilljeborg has even 
found a pair behind these in unusually large speci- 
mens, so that their number can rise to 24 pairs in 
all; indeed, Grube asserts that in one specimen he 
has counted as many as 26 pairs. They are, on 
the whole, of a very uniform structure, and exhibit 
all the characters of true branchial legs. They are, 
however, of essential importance, not only in respi- 
ration, but also in the admission of nourishment, as 
the organic particles in the water, on which the 
animal feeds, are whirled in towards the oral parts 
by the rhythmical movements of the legs. The 10 
or 11 foremost pairs are of about equal length, but 
after the 11th pair they begin to diminish rapidly, 
the hindmost pairs being exceedingly small and 
