den har temmelig tykke Leber, som ligge næsten til hin- 
anden, uden ganske at slutte sig sammen. 
I Bunden af denne Spalte syntes der at være flere 
fine Aabninger, men som paæ Grund af Dyrets Opbevaring 
i Spiritus vare saa sammentrukne, at de ikke med Bestemt- 
hed kunde sees, selv med stærk Loupe. 
Bagenfor Tilhængets Grund paa Bugfladen iagttoges 
den runde Mundaabning, Fig. 13, 6, der er stærkt foldet, 
og lidt til Siden af Mundaabningen, noget bagenfor denne, 
sees en yderst lille, rund Aabning, 
Huden er tyk, temmelig fast og ganske uigjennemsig- 
tig paa Kroppen, imedens den paa Snabelen er noget tyn- 
dere og gjennemsigtig. Den dannes af en Cuticula, - Fig. 
14, a, der er glasklar, uden Stribning og meget tynd paa 
Kroppen, saa at den endog er vanskelig at iagttage uden 
ved meget stærk Forstørrelse; paa Snabelen er den derimod 
meget tykkere, Fig. 15, a. 
Indenfor Cuticula er Epithelet, som dannes.af et Lag 
Cylinderceller, der have en bleg, gulgrøn Farve, ere 0.060”” 
lange, 0.008”” brede ved deres Grunddel. De blive sma- 
lere jo mere de nærme sig Overhuden og faa her Udseende 
af en Række Orgelpiber, Fig. 14, b. 15, 0. 
Disse lange Cylinderceller have temmelig tykke Vægge, 
ere forsynede med en stor mørkere Kjerne og et noget 
lysere Kjernelegeme, hvilke ere omgivne af et finkornet 
Protoplasma. 
Umiddelbart til dette Epithellag støder den egentlige 
Cutis, der udgjør et tykt, hyalint Bindevævslag, hvori findes 
en Mengde noget forskjelligt formede Bindevævslegemer, 
Is ME OP Mn Ge Å 
Indenfor Bindevævslaget er Muskelhuden, der dannes 
af 3 Lag: det ydre, circulere Lag (Ringmusklerne), som 
er temmelig bredt med stærke, tæt i hinanden liggende 
Muskelfibre, som ere sammenbundne med Bindevæv, Fig. 
14, d; det midterste Lag (Længdemusklerne), der ere bre- 
dere end de ydre Ringmuskler, Fig. 14, e, og hvis Fibre 
ere tykkere, og det mdre Ringmuskellag, som er yderst 
smalt, og hvis Fibre ere meget tyndere end de to fore- 
gaaendes, Fig. 14, f. Det indre Ringmuskellag er beklædt 
af Peritoneum, der har et Epithelovertrek; om dette er 
flimrende, hvilket er sandsynligt, kunne vi ikke afgjøre. 
Paa'Snabelen ere Cylindercellerne noget kortere, og 
her ligge Fibrene i Muskellagene saa langt fra hverandre, 
at Muskelhuden er tydelig gittret. 
Paa den indre Flade af Huden, just paa det Sted, 
der svarer til den tidligere beskrevne Spalte paa hver Side 
af den forreste Kropsende, sees en Række runde Aabnin- 
ger (vi talte 4 paa hver Side), hvilke vare omgivne af en 
rund Vold, der dannede ligesom en Sphincter om Aabnin- 
gen, som førte ind til Spaltens Bund, Fig. 11, a. 12, a. 
Her er et Slags Respirationsapparat, hvorved Søvandet 
40 
posterior, slightly inelming towards the dorsal surface; it 
has comparatively thick edges, near together, but not con- 
tiguous. 
The bottom of this fissured opening was apparently 
pierced with divers minute apertures, which, however, had 
become so shrunk and contracted (the specimen was pre- 
served in spirits) that even under a powerful lens they 
could not be plainly distinguished. 
Posterior to the base of the appendix, on the ventral 
surface, is seen the round buccal aperture, fig. 13, b, pro- 
minently folded; and a little aside of, and posterior to, the 
buccal aperture, occurs an exceedingly minute circular 
opening. 
The skin is thick, comparatively firm-textured, and 
quite opaque on the trunk; on the proboscis, it is some- 
what thinner and translucent. It consists of a cuticle, fig. 14, 
a, which is hyaline, without striæ, and on the trunk exceed- 
ingly thin, so thin indeed as to be with difficulty disting- 
uished even under a strong magnifier; on the proboscis, it 
is much thicker, fig. 15, a. 
Underneath the cuticle extends the epithelium, con- 
sisting of a layer of cylindric cells, in colour a pale yellow- 
ish-green, 0.060”” long and 0.008”” broad at the base; they 
become gradually narrower the nearer they approach the 
cuticle, where they closely resemble a row of organ-pipes, 
figs. 14, b; 15, b. | 
These long cylindric cells have thickish walls. are 
furnished with a large, dark-coloured nucleus, and a some- 
what lighter nucleolus, both surrounded by finely granulated 
protoplasma. 
Immediately adjoining this epithelial layer, extends 
the true cutis, consisting of a’ thick hyaline layer of con- 
nective tissue, throughout which corpuscles of connective 
tissue are abundantly dispersed, figs. 14, ¢; 15, c. 
Underneath the layer of connective tissue extends the 
muscular integument, composed of 3 layers: an outer cir- 
cular layer (the annular muscles), comparatively broad, 
with strong, closely disposed muscular fibres, webbed together 
by connective tissue, fig. 14, d; a medial layer (the long- 
itudinal muscles), broader than the outer annular muscles, 
fig. 14, e, and with thicker fibres; and the inner annular 
layer, which is exceedingly narrow, and with much slender- 
er fibres than the two foregoing layers, fig. 14, f. The 
inner annular layer is invested with peritoneum, having a 
thin epithelial tunic; but whether vibratile — which is pro- 
bable — or without cilia, we could not determine. 
On the proboscis, the cylindrical cells are somewhat 
shorter, and here the fibres of the muscular layer lie so 
far apart as to give the integument a distinct tessellated 
appearance, 
On the inner surface of the skin, extending along 
either side of the anterior extremity of the body, inside 
the fore-mentioned fissure, are seen a series of round open- 
ings (we counted 4 on each side), surrounded by a circular 
ridge, constituting a kind of sphincter round the opening, 
which leads down to the bottom of the fissure, figs. 11, a; 
12, a. Here (at the bottom of the fissure) is placed a 
