1864] 



Notes on some Indian and Burmese Helicidcz. 



241 



Of II cestus I have but three individuals, but they seem to form 

 merely a well marked local type of the species under consideration.. 

 They occur with or without the band ; the two varieties differing 

 slightly in other respects as well ; somewhat as H. Bequensis does 

 from II. scalpturita, the bandless variety of which it much resembles. 

 H. bqtatoeja, V. dem Busch. 



This species, though affording strongly marked varieties, is not a 

 variable one individually. We have in Burma the larger and more 

 common form of seventeen millemeters, which varies very slightly, 

 and a smaller form (H. Arakanensis, Th.) of only thirteen millemeters, 

 with a higher spire, which also varies very little ; and evidently con- 

 nects the species with II. Iluttoni, the largest specimen of which 

 from India in my possession is also thirteen mills, but with a flatter 

 spire than the small var. of H. rotatoria. There is also the very vari- 

 able race of II. Akowktongensis, Th., with its usually flattened spire, 

 holding a place between the large and small forms of II rotatoria. 



H. tapeina and II. Phayrei, Th. also claim a place near the type of 

 the species, the first nearly equalling a large II. rotatoria in size, whilst 

 closely resembling a small one in form, and the second differing from 

 the type rotatoria, in its narrower umbilicus, and more strongly mark- 

 ed sculpture. The little Indian U. Iluttoni follows, chiefly differing 

 in its small size, which may be averaged at eleven mills* 



Most aberrant of all comes II. Oldhami, B. with its depressed spire, 

 but it hardly differs more widely (save in one extra whorl), from a 

 large rotatoria m form, than specimens of H. Akowktongensis, Th. do 

 from one another. Intermediate forms are, however, requisite to con- 

 nect H. Oldhami, B. as closely as the rest are. 



II. rotatoria, V. d. Busch* Irawadi valley, below the frontier, 



Khasi Hills. 



Irawadi valley, above the frontier. 

 Arakan hills and Irawadi valley. 

 Irawadi valley. 

 Himalayas, Southern India, 

 Irawadi valley, above the frontier. 

 Helix eallaciosa, Fer., is another variable shell, presenting three 

 distinct types, as H. asperella, Pf. and its allied forms H. Nagporensis, 

 Pfr. and H. propinqua, Pfr. H. fallaciosa, Fer,, with its varieties and ally 

 U, Ilclferi, B, and II ruginosa^ Fer. with its ally II crassicostata, B, 



2 i 2 



H. tapeina, B. 

 H. Phayrei, Th. 

 II Arakanensis, Th. 

 H. Akowktongensis, Th. 

 H. Iluttoni, B. 

 H. Oldhami, B* 





