04 Messrs. J. C. Melvill atu? J. II. Ponsonby on 



Fit/. 1?. rotJocotyle atomon, Riid. Shell-gland complex ; ventral view. 



/>r?, yolk-duct; J'7?, yolk-receptncle ; KG, ov\Ai\ct. 

 Fig. 3. I.rpoilora rarhiern, (''<il)bi->id. Ventral aspect. 

 Fig. 4. l)itt(\ Male preniUil !ipp;uatusi ; peuis retracted ; dorsal view. 



Platk 11. 



Fig. 5. Stephanochnsnws haccatus, sp. u. Ventral aspect. 



Fig. 0. Ditto. I lea' I, .allowing spines ; ventral aspect. 



Fig. 7. Ditto. Oiiiliue of ovum. 



Fig. 8. Zoogonoides viriparus, Olsson. Ventral aspect. Fin, embryo. 



Plate III. 



Fig. 9. Zoogonoides viviparua, Olsson. Penis-sac; penis retracted, 

 showing the spines ; ventral view. 



Fig. 10. Derogenes cacozelus, sp. n. Right lateral aspect. 



Fig. 11. Hemiurus appetidiculatus, Rud., from Hippoglossus vulgaris. 

 Loop of uterus, showing ova with pigment-spots. 



Fig. 12. Head of Cvttus bitbalis, Euphr. Eye removed, to show pigment- 

 spots in the eye-socket. 



Plite IV. 



Fig. 13. Head of Coitus buhn/i.^, Euphr. Lower jaw divided and turned 

 to the sides ; gills bent back, to show the pigment-spots in 

 the roof of the mouth, following the course of tlie olood- 

 vessels. 



Fig. 14. Ascaropsis morrhtus, van Ben., from Gadm eegle/inus. a, cepha- 

 lic spines ; h, termination of annulating furrow ; c, end of 

 o?sophagus ; d, ova. 



Fig. 15. Ascaropsis morrhu^, van Ben., from Coitus bubalis. Highly 

 enlarged view of head, showing the two spines. 



Fig.lQ. Ditto. Tail; ventral aspect. 7/h', intestine ; An, ?Ln\.\ji. 



The drawings, with the exceptions of figs. 2, 4, 8, 9, were made from 

 pre.served specimens. 



VIII. — Descripticiisof Fifteen Terrestrial MoUusca from South 

 Africa. By Jame.s Cosmo Melvill, M.A., F.L.S., and 

 John Uenry Ponsonby, F.Z.S. 



[Plate VI.] 



Three years having now elapsed since our last conimunica- 

 tion *, we now venture to offer an eighteenth contribution 

 upon the .subject, mainly consisting of the descriptions of seven 

 Enneceaud several Helicoid.s, mostly collected by Mis.s Hickey, 

 Messrs. J. McBean, J. Farquhar, and M. C. Buniup, to 

 whom our best acknowledgments are due, while we would 



* Ann. & Mag. Nat. Hist. ser. 7, vol. xii. (December 1903), PP- ^<^-^ ^I'i- 



