319 
1906-7.] Helix pomatia with Paired Male Organs. 
spermatozoa are received and conducted by means of the vas deferens (V.D.) 
to the inner end of the muscular eversible tubular penis (P.), whose external 
aperture is only a short distance anterior to that of the vas deferens, and 
just behind the right lip. In the retracted condition the penis, which is 
CO. 
Fig. A. 
Fic.B. 
Fig. A. — Genital organs of Pythia scarabeus, L. x 5. After Plate (1897, p. 134, fig. 1). 
Fig. B. — Genital organs of Auricula myosotis, Draparnaud. x 16. After Pelseneer (1893. 
Plate xxii fig. 399). 
Acc.Gl., accessory glands on common duct ; Alb.G., albumen glands ; Cil.Gr., ciliated grove on 
the surface of the right side of the body; D., diverticulum, probably a mucous gland; 
Ep.Gr. , edge of lateral groove in the skin ; Fo., fold partially dividing common duct into 
male and female portions; G.O., opening of genital (common) duct to the exterior; H.D., 
hermaphrodite duct; M.O., male orifice; M.Retr,.P., retractor muscle of penis; O.T., 
ovotestis ; O.Y., opening of vagina to exterior; 0. V.D., point of origin of vas deferens; 
P. penis; R.S., receptaculum seminis ; Y.D., vas deferens; V.S., vesicula seminalis. 
provided with a retractor muscle, and vas deferens together form a U-shaped 
loop open at both ends to the exterior. 
A further stage is represented by another member of the family 
