DUBLIN NATURAL HISTORY SOCIETY. 59 



whole so great an analogy to those of the pulmonifera, that it is very- 

 likely, as the sperm and germ producing organs are isolated in the 

 former, so are they in the latter. The vas deferens in helix, with its 

 continuation, the testis, which is attached to the border of the uterus, 

 holds the place of the greatly elongate corresponding vessel in eolis, 

 here being, however, less distinction or separatiort of parts. 



EXPLANATION OF PLATE II. 



A. The entire reproductive apparatus, natural size — a, albumen 

 gland ; c, coecum ; d, dart-sac ; o, ovary ; ov, oviduct ; p, penis ; ou, 

 outlet ; V, vagina ; vm, multifid vesicles ; s, sperm-sac ; sd, spermatheca- 

 duct ; t, testis ; u, uterus ; vd, vas deferens. 



B. Vertical section through the dart-sac, enlarged, representing the 

 follicle, papilla, dart, protective valve, and orifice of vagina. 



C. Outline view of the testis, greatly magnified. 



D. A lobule of the ovary, enormously enlarged, exhibiting the ab- 

 sence of included lobule, and the isolated zoosperms at the aperture. 



E. Transverse section through the stilette, exhibiting the trenchant 

 outline and central perforation. 



BIBLIOGRAPHr. 



Berthelen. — Ann. des Sci. ITat. 



BuRDACH. — Quelques considerations sur le nidamentum. 



Carus. — Beitrage zur genauern kenntniss der geschlichts-organe und 



functionen einiger Gasteropoden. Miill. Arch., 1835. 

 CuviER. — Le Eegne Animal. Tome v. Mollasques. 

 Erdl. — Beitrage zur Anatomic der Helicon. Miill. Arch. 

 Pyfe. — Outlines of Comparative Anatomy. 1831. 

 Gegenbaur. — Vergleichenden anatomic. 1859. 

 Jones, E. — Animal Kingdom, and Article Gasteropoda, Cyclopasdia of 



Anatomy and Physiology. 

 Lister. — Exercitatio anatomica. London, 1684. 

 Meckel, H.— Miill. Arch., 1844, page 483. 



J. E. — Ueber ein neues Geschlect der Gasteropoden. 



MoQuiN -Tandon. — Histoire N'aturelle des Mollusques terrestres et flu- 



viatiles. 

 Pappenheevi. — in MiiU. Arch. 

 Siebolb. — Wiegemans Arch., 1836, i., p. 51. 

 VanBeneden. — Memoiresur I'anatomie de 1' Helix Algira. Brux. 1836. 



