14 LAND AND FRESHWATER 
EXPLANATION OF PLATH III. 
Fig. i: Microcystina rinkti, Morch, X 8. 
la. ; sculpture, x 50. 
_— : columellar margin, X 20. 
: partof mantle, x 8. aie right dorsal lobe ; /.d.Z., left 
dorsal lobe. 
: extremity of foot, x 8. From spirit-specimen. 
: generative organs. P., male organ; Sp., spermatheca ; 
vd., vas deferens ; D., dart-sace. 
> jaw, x 50. 
—— ——: teeth of the radula, central, median, and lateral, x 1210. 
: ditto, ditto, X 360. 
warnefordi, n. sp., X 7. 
: sculpture, X 50. 
moerchiana, n. sp., X 4. 
a : sculpture, X x 50. 
10. cryptomphalus, n. sp., X 7. 
104. ——: sculpture, X 50. 
106, —— : columellar margin, x 20. 
ie harrietensis, n. sp., X 8. 
lla. : sculpture, X 50. 
oR ftom 
ey ————— 
a. 
DO DANSD 
On the Land-Molluscan Genus Cryptosoma, and Description 
of the Animal of Cryptosoma prestans, Gould. 
(Plate IV.) 
The genus Cryptosoma was created in 1857 by Mr. W. Theobald, 
of the Indian Geological Survey, for a shell common at Moulmain, 
named Vitrina prestans by Gould. Mr. Theobald’s original descrip- 
tion in the J. A. S. Bengal, no. iv. p. 252, is very brief, and runs 
thus :—‘ Testa vitrine simile, sed robustiore. Peristomate obtuso haud 
tenui. Animale penitus intra testam retractile, et, in cestivationis tem- 
pore, solido epiphragmate obtecto. 
“C. prestans (Vitrina prestans), Gould. Maulmain, Martaban, 
Tenasserim valley. 1 have separated this shell from Vitrina, as the 
animal is perfectly retractile, and the peristome is thicker than in 
Vitrina proper, and not membranous. It is common in holes in 
laterite at Martaban, and not rare throughout the Tenasserim valley. 
Its colour is a bay-olive Cajiput green.” 
The genus was therefore founded partly on the characters of the 
animal, and is therefore far better than the meagre shell-characters 
on which so many genera have been created. It is curious the 
truncate form of the foot with the mucous pore was not also men- 
tioned, which is the principal outward character that distinguishes 
it from Vitrina with its long pointed foot. I had long wished to 
get a specimen of the animal of this species, its shell being peculiar, 
