494 



VAGINULIBJE. 



base of the ovary likewise has not been ascertained, but no doubt 

 is left that the female genital orifice does not occur on the 

 lower surface of the mantle, as is the case without exception 

 in all VcKj'invli, an anatomical feature of sufficient importance to 

 warrant generic separation. 



The male organ is near the head (fig. 160^5, m, n, 6) and, with 

 the external aperture, placed directly beliind the lower tentacle ; it 

 consists here of a penis (fig. IGO^i^, n), very small as compared with 



"Fig. 101. — Lconardta nevilliaiia. 

 (Copied from Ann. Mus. Civ. Geneva.) 



the size of the animal — perhaps dependent upon seasonal change — 

 and a curious and relatively enormous multifid gland (fig. 160^ B, 

 m) communicating with it. This gland has also been observed in 

 many species of Vaginulus but in the present case it attains an 

 exceptional development. It consists of a vestibule 7 mm. long, 

 with a diameter of about 2-5 mm. which gradually increases and 

 from which from 60 to 70 caeca branch off like the roots of a tree- 

 trunk (fig. 160*^ a) of a pearly white, long, fiUform (about | mm. 

 in diameter), densely ramified, folded upon themselves at various 

 intervals and gathered into a bundle by a pellucid membrane. 



