98 THEBA CARTUSIANA. 
striation. APERTURE broadly lunate, margins rufous brown and slightly expanded, 
but more dilated basally, and slightly expanded over the narrowly perforate 
UMBILICUS. 
Average size of British specimens: Diam., 12 mill.; alt., 7 mill. Average weight 
of British shells: 1°08 grains. 
INTERNALLY, the KIDNEY or precordial gland shows as a very elongate and 
recurved organ, bearing some resemblance to the blade of a seythe; it is of a pale 
yellowish brown, with its venation quite perceptible through the shell. 
outa 
exes 
[(- ee 
Fic. 145. Fic. 146. 
Fic. 145.—Proximal portion of the alimentary canal of 7. carvtusiana, shewing the cesophagus, 
salivary glands, crop, stomach, and the origin of the gut, x 3. 
Fic. 146.—Kidney or renal organ, also showing its close association with the heart, x 3. 
The REPRODUCTIVE ORGANS are chiefly remarkable for the apparent retention of 
a DART SAC and ACCESSORY GLAND similar to that seen in certain Hygromice, but 
the dart sac shows no signs of the presence of a dart, though in lieu of that weapon 
the distal portion of the sac has become elongated into a narrowly cylindrical 
c#CUM which, probably by eversion, functions as an excitatory organ. The ovo- 
TESTIS is rather compact with a fairly long HERMAPHRODITE DUCT closely convolute 
and thickened towards its lower end; the ALBUMEN GLAND is elongately lingui- 
form, distinctly concave on its inner face, and of a yellowish colour with some- 
times a greenish tinge; the VESICULA SEMINALIS is elongately ovoid, rugose, and 
of a glandular character ; the OVIDUCT is of a transparent grey, distinctly saceulate, 
and the prostate is granulate, of an opaque creamy-white, broad, and conspicuous ; 
Fic. 147. Fic. 148. Fic. 149. 
Fic. 147.—Reproductive organs of Theba cartusiana (Miill.), Lewes, X 3, Mr. C. H. Morris. 
Fic. 148.—Proximal end of the reproductive organs of 7. cartusiana more highly magnified. 
Fic. 149.—Enlarged portion of distal end of reproductive organs of 7. cartusiana. 
ag. and a.gi. albumen gland; d. or s¢#. degenerate dart-sac, nascent sarcobelum or excitatory 
organ ; ef. epiphallus ; 7. flagellum ; 2.¢. hermaphrodite duct ; #z.g¢. mucus-gland ; o/. ovotestis ; 
ov. oviduct ; f.s. penis-sheath; s.d. and sf.d. sperm duct; sf. spermatheca; v.d. vas deferens; 
v.s. vesicula seminalis. 
the SPERMATHECA is bluntly triangulate, and of an opaque white, with a fairly 
long and moderately stout stem; the VAGINA or free oviduct is fairly wide ; the 
VAGINAL MUCUS GLANDS are tinged blue, composed of two groups of simple, bifid, 
or even trifid ceca, 3-5 mill. long, while immediately beneath them are a degenerat- 
ing DART-SAC and accessory gland, which except for a digitiform cecal outgrowth 
from the distal end of the sac, outwardly present the normal aspect, and are very 
constant in size and shape, but at present no trace of a dart or gypsobelum is 
detectable, the function of the lost organ being probably now performed by the 
vermiform distal outgrowth of the dart-sac, which may function as a sarcobelous 
