FERUSSACIA. 217 



vets deferens; the retractor muscle is given off close to this. 

 The spermatheca is elongately pear-shape. No dart-sac was 

 observed in the three specimens examined. The ovotestis 

 in one specimen appeared to be a mass of globosely pear- 

 shaped follicles united at their basal ends into a duct ; but in 

 two specimens there was found near the apex, embedded in 

 the livers, a dark triangular-shaped organ, which, when ex- 

 amined more closely, was trilobed, uniting in a single duct, 

 streaked and coloured black along its straight terminal margin, 

 and may possibly have consisted of closely packed bundles of 

 spermatozoa. The hermaphrodite duct was not made out, 

 nor the albumen gland; and I most unaccountably did not 

 notice the exact position, with respect to the right eye-tentacle, 

 of the generative aperture." (G-Aust.) 



The soft parts of F. folliculus from Madeira, examined by 

 Watson (P. Z. S. 1877, p. 333, 334) resemble those of the 

 other large Madeiran species, but the mantle was apparently 

 somewhat less broadly reflexed over the shell. In external 

 color it is quite unlike F. gronoviana " yellow, towards the 

 tail slightly orange, towards the head with a faint tinge of 

 gray, which is darker towards the ends of the tentacles. The 

 sole of the foot is lemon-colored." 



In the Madeiran species melampoides, tornatellina, triticea 

 and oryza " the mantle extends beyond the edge of the aper- 

 ture all round. It is thinly spread over the outside of the 

 shell, and extends like a tongue backwards behind the pos- 

 terior corner of the aperture. The tail carries a mucous 

 gland and is abruptly truncate " (pi. 42, fig. 72, F. tornatel- 

 lina, after Watson). The jaw has about 60 slightly converg- 

 ing ridges. The teeth resemble those of F. gronoviana. 



The following fossil forms of the folliculus group have been 

 described : 



Ferussacia convoluta Paladilhe, Revue des Sci. Nat., Mont- 

 pellier, ii, 1873, p. 46, pi. 2, f. 7-9. Pliocene, Montpellier. 



Ferussacia obovata Paladilhe, t. c. pi. 2, f. 10-12. Pliocene, 

 Montpellier. 



Ferussacia (Folliculus} pollonerce Sacco, 1885, and F. (F.) 

 tassaroliana Sacco, 1888, are Pliocene species of the Villa- 



