180 ZO^ITJD JE. 



possessing a solid or tubular calcareous dart, of which Parmanon 

 o£ Java &c. may be taken as the type. IS^one have hitherto been 

 recorded from India, but they may be looked for in Eastern 

 Burma. Many such genera are now known (Parmarion, M'lcro- 

 ^larmarion, Collingea, Wiegmannia, Parmunculns, Crypioseviehis, 

 Philipinnella, ParmeJIa, &c.) which might well constitute a sub- 

 family — the Parmarionina;. Genera such as Damayaniia, also 

 haying' calcareous darts, approach species of the subfamily Durgel- 

 lino', the radula having very numerous and similar teeth in the 

 row. 



In Parmarion and allied forms, such as Damayaniia, the deve- 

 lopment of the mantle which envelops the shell in life appears 

 to have had its origin on the margin of the mantle-zone, and 

 extended from its periphery equally and inwardly to the central 

 slit in some and carried further to a complete covering in others. 

 It has not been derived from distinct right and left shell-lobes 

 as in Austenia and Girasia, and these terms are not therefore 

 applicable.] 



[Genus CRYPTAUSTENIA. 



Cr^-ptaustenia, Cocherell,A. M. N. H. (3)_ vii, 1891, p. 99 (no 

 description : as a section of Helicarion) ; id. Nautilus, xii, 1898, 

 p. 10. 



Type, C. succinea, Eeeve. 



Range. Sikhim and Eastern Himalaya ; Lower Bengal and to 

 Cachar.] 



Shell imperforate, thin, diaphanous, smooth, depressed ; whorls 

 3-41, rapidly increasing, the last large and rounded ; aperture 

 large, oblique ; peristome simple, more or less membranaceous. 



The animal has the shell-lobes of the mantle broad but divided 

 from each other and almost or quite concealijig the shell when 

 fully expanded. The dorsal lobes cover much less of the back of 

 the foot than in the latter genus. Peripodial groove and mucous 

 pore strongly developed, a projecting lobe above tlie latter. 

 Genitalia cMefiy distinguished from Macrochlamys hy the absence 

 of a coil for the attachment of the retractor vmscle of the penis. 

 Radula with a tricuspid rhachidian tooth and rather numerous broad 

 inner laterals hi- or tricuspid, together with a much smaller number 

 of outer pointed bicuspid laterals than in typical Girasia, and the 

 outer cusp of these is outside remote from the end. 



This group is at once distingtiished by its shell from Girasia 

 and Austenia. It chiefly differs from Vitrina by having a mucous 

 pore, and the genitalia are quite different. 



a. Species from the Eastern Himalayas. 



277. Cryptaustenia succinea, Rv. (Vitrina) Conch. Ic. Vitrina, 1862, 

 pi. ii, tig. 8 ; //. <S- T. (Vitrina) C. /. 1876, pi. 75, tigs. 7, 10. 

 Vitrina planospira, Bs. A. M. N. H. (3) iii, 1859, p. 271 ; Pfr. 

 Man. Hel. \, 1868, p. 14 ; Goihcin-Austen (Austenia), Mol. hid. 



