281 



NOTES ON TROCHONANINA AND OTHER GENERA OF LAND 

 MOLLUSCA, WITH REFERENCE TO THE GENERIC POSITION 

 OF MARTENSIA MOZAMBICENSIS AND OTHER SPECIES. 



By Lieut. -Colonel H. H. Godwin-Axjsten, F.E.S., F.Z.S., etc. 



Bead May lOth, 1895. 



PLATE XIX. 



The following notes have been made after the examination of a species 

 of land-shell collected by Dr. J. "W. Gregory, when on his well- 

 planned, well carried out, and most interesting journey in Eastern 

 Africa, during 1893, accounts of which have been given in papers 

 read before the Geological and Geographical Societies in 1894. I am 

 indebted to Mr. Edgar Smith for the specimens I now describe. 



Mahtensia Mozambicensis, Pfr. 



Helix Mozambicensis, Proc. Zool. Soc. 1855, p. 91, pi. xxxi, fig. 9. 



IVochomvrpha Pfr , Vers., p. 132. 



Albers, Die Heliceen, 1860, p. 60. 



Martensia Semper, Moll. Philippinen, 1870, p. 42. 



Trochonanina V. Martens, Monatsb. Akad. Berlin, 1 878, p. 289. 



The shell is well known and fully described ; I therefore only give 

 its size, which is 10-13 mm. in diameter, but it varies much in height. 



Animal. — From spirit specimen (Fig. 1). Length 11 -5 mm. Black 

 in colour throughout, perhaps a very dark grey in life. The pallial 

 margin is wide ; the principal linear markings on the side of the 

 foot are regidar, distant, and very conspicuous ; the divisions along 

 the pallial line are also very oblong. The mucous pore is a linear 

 slit, not extending to the sole of the foot behind. It is overhung by 

 a very long, pointed, horn-like protuberance, which is a continuation 

 of the keeled foot ; this even in the spirit specimen is very long and 

 sharp-pointed, so that when fully extended in life it must present a 

 most remarkable appearance (Fig. \a). The mantle has no shell lobes; 

 the left neck lappet is apparently separated from the right one, and is 

 long and naiTow in form, with an indication of a separate posterior 

 lappet. The right neck-lobe was not well preserved in the two 

 specimens I received, but there did not appear anything very different 

 on that side from most other allied forms. The sole of the foot has 

 a central area. The jaw is almost semicircular in outline, the cuting 

 edge concave, with a strong and large central convex projection. 

 The radula is broad — 



30 : 12 : 1 : 12 : 30 about, 

 or 42 : 1 : 42 



The centre tooth is elongate, with small cusps at the base on either 

 side ; the admedian teeth are broad, with the cusp only on the outer 



