iv INTRODUCTION. 
the Asiatic Society of Bengal’ *, summing up what has been 
done in Indian conchology, says :—‘ The same decade (1870 
to 1880) has seen the completion of a series of illustrations, 
many of them well executed, of Indian land and freshwater 
shells, the ‘Conchologia India’ of Hanley and Theobald. 
The work is mainly due to Mr. Hanley, upon whom the 
whole of the editorial labour has falien, Mr. Theobald having 
been absent in India during the publication. Whilst it is 
impossible to avoid regretting that more complete illustrations 
of most of the species have not been given, and that some 
additional details have not been furnished in the accompany- 
ing letterpress, it is unquestionable that the plates are a 
valuable contribution to the knowledge of Indian Mollusca. 
....+. ‘lwo other rather important works on Indian land 
and freshwater shells have been issued since the completion 
of the ‘Conchologia Indica.’ One of these is Mr. Theobald’s 
‘Catalogue of the Land and Freshwater Shells of British 
India,’ the other Mr. G. Nevill’s ‘ Hand-list of the Mollusca 
in the Indian Museum, Calcutta,’ Part I. ..... This 
work is especially important for the large number of exact 
localities given; ..... and in many points the classification 
adopted for the Helicidz of India is a considerable improve- 
ment on any thing that had previously been published. At 
the same time there is, I believe, very much more to be done 
before these puzzling shells are properly arranged.” 
Every illustrated work of this kind is a step in advance in 
the study of Natural History; and I propose, besides the 
figuring of new species, to take up those minute forms that 
have not been sufficiently enlarged and well drawn in the 
‘ Conchologia Indica,’ such as the small forms of Helices, 
and those among the Cyclophoridz and Helicinide—A/lyceus, 
Diplommatina, Acmella, Georissa, &c. 
* “ Contributions to Indian Malacology.—No. XII.” (Dee. 1, 1880). 
