1S65.] Contributions to Indian Malacology. 89 



bands, and passes into a shell closely resembling H. Pegucnsis, Bens., 

 a more solid form, shells approaching which closely in every character 

 except in being less solid, were found on the Shan hills, east of Ava. 

 Mr. Benson considers these shells distinct from H. Peguensis, but there 

 can be little doubt of their forming a link. The typical variety of 

 H. scalpturita abounds near Mandele. H. Zoroaster, Theobald, is a 

 large H. similaris, and occurs abundantly at Thayet Myo and less so 

 at Prome. H. bolus, Bens., abundant near Thayet Myo and Prome, 

 is sometimes marked hj a coloured band like that of H. similaris, and 

 varies greatly in the height of the spire. The type is a well marked 

 forcu, far more globose than the others, but yet it passes, by impercep- 

 tible gradations, into similaris. H. delibrata, Bens, is also allied to 

 similaris although classed in a different section or subgenus by both 

 Albers and Pfeiffer; it unites Dorcasia with the Trachea group, 

 (_£T. asperella and its allies). H. delibrata is not rare throughout 

 Arakan ; it occurs at Akyab, and in Pegu it is found at Akoutoung 

 and other places ; when fresh it has a subhispid epidermis, and fre- 

 cpiently a rufous band above the periphery, like similaris and asperella. 



Somewhat allied to the similaris group, but yet forming a distinct 

 and well marked section, are H. tapeina, Bens., and its allies H. rota- 

 toria, v. d. Busch, H. Oldhami, Bens., and H. Hidtoni, Pfr. To 

 these, two other species have been added by Mr. Theobald, viz. : 

 H. Pliayrei and H. Ahoutongensis. The type appears almost peculiar 

 to the Malay countries, one species only, H. Hidtoni, occurring upon 

 the Himalayas and other Indian mountains, and none in the plains of 

 India. 



H. Oldhami, Bens, is a well marked and easily distinguished form, 

 with almost flat spire, very wide umbilicus, and the last whorl sub- 

 angulate above the periphery and swollen beneath. The epidermis, 

 when in good order, is subhispid, as in several other species of the 

 group. This form was first found by Dr. Oldham at Mya Leit Doung, 

 a few miles south-east of Ava, and I afterwards met with it in the 

 Arakan hills, on the road between Prome and Tongoop. 



The other species pass into each other in the most perplexing 

 manner, and there scarcely appears any choice between increasing their 

 number indefinitely, and classing all together as varieties of one species. 



The little form known as H. Hidtoni, Pfr., is perhaps more easily 

 distinguished than most of the others, as it is singularly constant in 



