500 



JAlsELLID.'E. 



" Generative Organs. — Tlie ovotestis, hermaplirodite duct, and 

 albuinen-glaud were not made oat. The oviduct is much coii- 

 V(j]uted fur a short distance and then extends in a long straight 

 duct to the generative aperture ; the prostate is of some length, 

 the vas deferens running parallel to the straight portion of the 

 oviduct down to a short bulbous expansion, to which it is probable 

 the retractor muscle is given oft ; but this was not found in either 

 specimen examined. The spermatheca is of very great length ; a 

 long thin tube terminating in a i-ound ball-like expansion, which 

 is like in this respect to H. maiUardi. Bijalima.v andamanica, 

 however, differs from the Bourbon species (1) in the form of the 

 jaw, which has no indication of a central projection ; (2) there is 

 considerable divergence in the shell, and I give a drawing of that 

 of H. perlucid'us, from Mauritius, received by me from Mr. (t. 

 Nevill, wliich shows the apex to be very attenuate and sharp, and 



Fig. 1G4. — Hiiallmax andamanica. Jaw and radiila. 

 (Copied from Moll. India.) 



there is a distinct greenish epidei'mis ; (3) the dental formula is 

 different; (4) Pischer does not indicate the position of the anal 

 aperture, which, situated in H. andamanica so far back on the 

 posterior right margin, is of extreme importance, so that if other- 

 wise in Hyalimax of Bourbon, and in its usual position adjacent 

 to the respiratory orifice, it may render it nece^^sary to place the 

 Indian form in another subgenus, which I would name Jarava, 

 from the name of the aboriginal tribe that inhabited the South 

 Andaman Islands. In this case a subfamily Hyalimacin^ would 

 include ]. Hi/alima.v (perlucidus. Isle of France; mauritiamis. 

 Isle of France; nia.iJlardi, Bourbon), and 2. Jarava {reinhardt, 

 !Nicobars; aHd(imanica, AiKlamans ; viridis, Arracan). 



