at Mundskiven faar Udseende af et Hoved, der altid bøier 
sig mod Bugfladen, Fig. 2. 
Noget foran Kraven; som oftest skjult af denne, sees. 
to meget smaa Aabninger, skilte fra hinanden ved en 
liden Fold, af hvilke den for Generations-Organets Udfor- 
selskanal er lidt fremspringende, imedens den anden, der 
fører ind til Stenkanalen, er i Niveau med Huden. Paa 
Rygsidens bagerste Del findes den store, runde Kloakaab- 
ning, «Fig. 1, 0. 
Paa begge Sider af Kroppen, just der hvor Bug 
og Ryg støde sammen, sees en Rekke tykke, lange, 
koniske Fødder, der fortsættes omkring Dyrets bagerste 
afrundede Ende, Fig. 2 c, c I Regelen er der 5 paa 
hver Side, og 6 omkring Enden, ialt 16; men paa et An- 
tal af 40 Exemplarer talte vi 18 Fodder paa et, og 14 
paa to. Å 
Fodderne ere paa Siderandene stillede ligeoverfor 
hverandre, og det første Fodpar tager i Almindelighed sit 
Udspring lidt bagenfor Kraven, — dog varierer dette noget; 
thi hos enkelte staa første Fodpar ganske i Linie med Kra- 
ven, imedens de hos andre staa temmelig fjernet fra den, 
Fig. 1, 2. En lignende Variation finder ogsaa Sted med 
Hensyn til Afstanden imellem Fødderne indbyrdes, saaledes 
nemlig, at der stundom kan være et stort Rum mellem 
første og anden Fod, og hos enkelte andre staa disse Fød- 
der tættere sammen. De kunne ikke ganske indtrækkes, 
og naar deres Spids indkrængedes, fremkom en Grube. 
Ved Roden af hver Fod iagttages paa Bugfladen, 
gjennem den temmelig klare Hud, en aflang Fodampulle, 
Fig. 2, d, der ligger fæstet til den mdre Hudflade, og fra 
hvis indre Ende udgaa to Muskelbaand, der strække sig 
‘hen til den midterste Længdemuskel, Fig. 2, e. 
Legemets Overflade er ved 5 Længdemuskler delt i 
5 Felter, 2 tilhørende Biviet, 3 Triviet. Disse Længde- 
muskler have temmelig tykke Rande, men ere meget tynde 
paa Midten, saa at den derunder liggende Nervetraad skin- 
ner igjennem og giver sig tilkjende som en skarp Lime, 
der ligesom deler Muskelen 1 to Dele, Fig. 2. 
Huden. 
Huden er meget gjennemsigtig, tynd, glat, blød, slimet 
og kontraktil. 
Cuticula er overordentltg tynd, vandklar, strukturløs 
og tæt bunden til det underliggende Fpithel eller Subcuti- 
eularlag, hvoraf den er et Produkt, Fig. 10, a. 
Epithelet bestaar af et Lag temmelig lange Cylinder- 
celler, som ere bredere ved Grunden, der er føæstet til 
Corium, og smalere mod Cuticula, Fig. 10, b. Dels imel- 
call it, the body grows narrower and more cylindrical, 
forming, as it were, a neck, the anterior extremity of the. 
trunk having a somewhat greater breadth, which gives to 
the oral disk the appearance of a head constantly inclining 
towards the ventral surface, fig. 2. ‘i 
A little in advance of the collar, by which as a rule 
they are hidden, occur two minute openings, separated from 
each other by a small intervening fold; one of these, the 
genital pore, is somewhat gibbous, whereas the other, leading 
to the “sand-canal,” or .madreporic tubercle, is in a plane 
with the integument. On the posterior portion of the dorsal 
surface o¢eurs the large circular cloacum, or anal orifice, 
me, dl, O, | 
On ‘either side of the body, exactly in the lime of 
junction of the dorsal and ventral regions, age seen a series 
of long, thick, conic suckers, extending round the curved 
posterior extremity of the animal, fig. 2, c, c. Most individ- 
uals have 5 jon each side, and 6 bordering the extremity, 
16 in all; but of 40 specimens examined, one had 18 
suckers, and two, 14. 
Along the lateral margins, these suckers. are disposed 
in opposite series, the first pair generally having its origin 
a little posterior to the jugal protuberance; this, however, 
is not a strictly constant feature, the first pair of suckers 
being in some examples contiguous to the collar, whereas 
in others, the space between is considerable, figs. 1; 2. A 
corresponding variation as to distance characterises, too, the 
arrangement of the suckers ter se; the first and’ second 
suckers, for instance, are in some individuals comparatively 
distant, but in others more closely set. They do not any 
of them admit of being fully retracted, and on forcibly 
- invaginating the points, a small cayity or depression was 
produced. 
At the base of every sucker, on the ventral plane, 
may be discerned through the semi-translucent membrane _ 
an ovate pedal ampulla, fig. 2, d, attached to the inner 
surface of the skin, from the inner extremity of which 
two muscular bands are seen to issue, extending from’ 
thence to the medial longitudinal muscle, fig. 2, e. 
Five longitudinal muscles divide the upper surface of 
the body into as many segments, two of which constitute 
the bivium, and. the remaining three the trivium. These 
longitudinal muscles have thickish margins; but in the 
middle they are exceedingly thin, and the nervous chord 
beneath is distinctly perceived, bisecting, as it were, like a 
sharply drawn line, the muscle it traverses, fig. 2. 
Skin. 
The integument is in a high degree translucent, 
tenuous, soft, smooth, mucid, and contractile. 
The cuticle is remarkably’ thin, pellucid, simple, and 
closely webbed to the epithelium, or subcuticular stratum, 
underlying it, of which indeed it is a product, fig. 10, a. 
The epithelium consists of a layer of comparatively 
deep cylindric cells, somewhat broader at the base, which 
is attached to the corium, than at the apex, or cuticular 
