MOLLTJSCA OF INDIA. 



139 



luflian region : we know many species to extend along certain strips 

 of the mountain masses, but in the case of very few can we at present 

 define both ends of such strips. We only know that within certain 

 limits a considerable change in the molhiscan fauna takes place. A 

 great deal of accurate observation of this kind has still to be made, 

 much more material preserved in spirit is required, and many hours 

 of work must be gone through, before we shall be able to place many 

 a species in its true generic position. 



As to the inaccuracies pointed out by my critic, I have nothing 

 to complain of, and am glad they are referred to ; it is a healthy 

 thing to be found fault with. It is a very moot point whether 

 the discovery of Bulimm of Scopoli being a freshwater form and 

 its suppression have been of any utility to conchologists. Bulimas 

 had "' taken hold"' and been in universal use by many writers for a 

 great main group of shells, and it is difficult to throw off the idea it 

 has conveyed for years. In making changes like this, some con- 

 sideration should be made for views held by the early writers and 

 how a term grew into use. However, the same puzzle meets the 

 ornithologist, and this is not the place to revive such a controversy. 

 Moreover, it is very difficult for those who began collecting long 

 ago to think of Bulimus as an inhabitant of fresh water. 



As to classification, the time has really not arrived when it should 

 be attempted ; although many thirsty souls are eager to see it 

 finished, it should be ]Dut off until we know more about the many 

 and even large species awaiting examination, such as hasileus, 

 hasilessa, ampidla, saturnia, &c. In my address to the Malacological 

 Society I ventured upon the phylogeny of the Macrochlamidse ; but 

 even here the position of MacrocJdamys pedina cannot be accepted 

 as final, on account of the similarity of its genitalia to the type of 

 the Ariopliantinse. A comparison of Indian genera is necessary 

 with those which have been founded during the past few years by 

 naturalists who have been doing good work in the Malay Archipelago, 

 China, &c., among whom I may mention 0. v. MijUendorff, E. v. 

 Martens, L. Pfeffer, P. and F. Sarasin, &c. 



For a very considerable portion of the contents of this Part, and 

 the light it throws on the morphology of the Indian Land Mollusca, 

 I am indebted to the active interest and assistance of Mr. 0. Collett, 

 who has sent me so many species, beautifully preserved, from 

 Ceylon. He and Mr. Preston have given quite an impetus to the 

 study of the Indian species, and we have had valuable papers from 

 Mr. E. E. Sykes on these collections. To Mr. Phipson, of Bombay, 

 both direct and through Mr. W, T. Blanford, I am also under 

 obhgation for species in alcohol. Major Thurston, of the Madras 

 Museum, and Lieut. Stanley Flower, in Siam, have also sent me some 

 species of much interest, for which my best thanks are due. 



In conclusion, I may add, I have been able of late to determine 

 the generic position of the following Ceylon and one South-Indian 

 species : — Microcystis ? thivaitesi, Pfr. = sunvis, Jousseaume, and 

 MacTocldamyn ? circumsctdjJta, Sykes, both belong to Phdalanka ; I 

 also find that Thysanota criniyera, Bs., hiciUaia, Pfr.. and hispida, 



