180 ZCXNITIDJE. 



possessing a solid or tubular calcareous dart, of which Parmarion 

 of Java &c. may be taken as the type. None have hitherto been 

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

 Burma. Many such genera are now known (Parmarion , Micro- 

 parmarion, Collingea, Wiegmannia, Parmunculus, Cryptosemelus^ 

 Philippinella, Parmella, &c.) which might well constitute a sub- 

 family the Parmarionince. Grenera such as Damayantia, also 

 having calcareous darts, approach species of the subfamily Durgel- 

 lince, the radula having very numerous and similar teeth in the 

 row. 



In Parmarion and allied forms, such as Damayantia, 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 CKYPTAUSTENIA. 



Cryptaustenia, Cockerell, 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 rnembranaceous. 



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

 from each other and almost or quite concealing 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 the latter. 

 Genitalia chiefly distinguished from Macrochlamys by the absence 

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

 Iladula with a tricuspid rhachidian tooth and rather numerous broad 

 inner laterals bi- 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 distinguished 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 ; H.$T. (Vitrina) C. I. 1876, pi. 75, figs. 7, 10. 

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

 Hon. Hel. v, 1868, p. 14 ; Godwin-Austen (Austenia), Mol. 2nd. 



