HELIX PISANA. ol 
oval, borne upon a long and slender duct, from which arises a stout and well 
developed DIVERTICULUM, the whole being closely attached to the OVISPERMATO- 
puct by a richly vascular membrane, as in the He/icigona; the FREE OVIDUCT 
is well developed and bears a pair of long, slightly sacculate and tubular yellowish 
or brownish MUCUS GLANDS, which are most capacious at the ends, and partially 
Fic. 411. Fic. 412. 
Fic. 411.—Reproductive organs of //edix pisana Miiller, from Jersey, x 2. 
Fic. 412.—Proximal portion of the Reproductive organs of //e/ix fisana Miiller, x 4, showing the 
character of the epiphallus. 
a.g. albumen gland; d. diverticulum ; ¢.s. dart sac; ef. epiphallus ; #.g/. vaginal mucus glands ; 
ot. ovotestis ; #. penis sheath; 7. penial retractor ; sf. stem of spermatheca ; sf.d. sperm duct; oz. 
oviduct ; v.d@. vas deferens. 
embrace the dart sac, in which feature, as well as in their simplicity, they conform 
to the arrangements in Helicigona arbustorwn and H. lapicida; the PENIS SHEATH is 
somewhat long, with a median thickening, which is of an opaque yellowish-white, 
-the ends being of a transparent azure-white; the RETRACTOR MUSCLE is of a trans- 
parent light azure, and is fixed at its distal end, which is continued to form a long 
and stout EPIPHALLUS, Which is abruptly bent, and lies parallel to the penis sheath, 
to which it is fixed by muscular tissue; it is proximally of a light azure, but becomes 
bulkier and of an opaque milk-white in the distal half, and shows by transmitted 
light several series of closely arranged transverse markings, arranged longitudin- 
ally, and probably indicative of an internal structure which will impart a specific 
facies to the spermatophore formed therein ; there is no flagellum, which has probably 
hecome atrophied and lost, and the vas deferens enters the epiphallus terminally. 
The DART SAC or stylophore is small and obovate, of a pearly-white aspect, and 
is encircled externally by a prominent median external ring or girdle, suggesting 
the form of an acorn. The immature dart-sac before the secretion of the dart takes 
place, shows in longitudinal section a tripartite lumen or cavity of which the basal 
limbs surround the tubercle which supports the dart on the fundus of the sae and 
secretes the annulus, the remaining limb of the cavity extending in the direction 
of the future aperture from which the dart will be protruded. 
Fic. 413. Fic. 414. 
Fic. 413.—Section through the immature dart sac of //ediv fisana, before the formation of dart, » 6. 
Fic. 414.—The fully mature Gypsobelum or love dart of //e//v fisana, X 10, 
Fic. 415.—Section through the median portion of the Gypsobelum or love dart, showing the struc- 
ture and arrangement of the blades, x 30. 
The DART or gypsobelum is very small (scarcely 25 mill. in length) for the size 
of the animal, and searcely larger than that of He/ivel/a caperata, Int in strueture 
it entirely conforms to those of the Pentatweniate group. It has a short straight 
shaft, expanding rather abruptly at the base, and provided with four symmet- 
