414 Mr, W. H. Benson on the Geographical Distribution 



It does not appear to have been detected by any subsequent 

 collector in the environs of Darjiling. Nearly equal in size to 

 C. Himalayanus, Pfr., from the same locality, it is distinguished 

 from it by its form, depressed last whorl, wide umbilicus, sculp- 

 ture, vertically of the angle at the upper part of the mediocre 

 aperture, and by the colour of the peristome. There are indi- 

 cations of a broad light chestnut zone below the dark band at 

 the periphery. The compressed character of the last whorl 

 presents a strong contrast to the subglobose form of C. Hima- 

 layanus in that part. 



Geographical Distribution of the Genera of the Cyclostomacea 

 in Hindostan. 



In the 8th vol. of the New Series of the 'Annals/ I attempted 

 a view of the geographical distribution of the Indian species of 

 Cyclostoma as then known to me. I am now able to add some 

 species to the list, and it will prove interesting to exhibit the 

 manner in which the different genera, as recognized by Pfeiffer, 

 are distributed, from the Himalaya to Cape Comorin. 



Cyclophorus, Montf. 



Beginning with the largest and most extensively spread form, 

 Cyclophorus, we find it at Darjiling in the Sikkim territory, 

 occurring at an elevation of 7000 feet, under the gigantic types 

 C. Himalayanus, Pfr., C. Tryblium, nobis, C. Stenomphalus, Pfr., 

 the variety which I designated as C. Aurora, and the small 

 widely umbilicated C. Phmiotopicus, nobis. This region carries 

 a subtropical vegetation to a great elevation. At some hundred 

 miles to the west and north, at the foot of the Rohilkhund 

 Himalaya, where a similar vegetation begins to give way to more 

 European types, we find the outpost of the genus, in this direc- 

 tion, in C. Exul, nobis ; and, as might be expected, the shell is 

 dwarfed in size, light in structure, and modestly coloured. It 

 may be remarked, in illustration, that C. turgidus, Pfr., is 

 found near the Chinese coast, as high as Loochoo, in a parallel, 

 however, less northerly than Bhamoury. The influence of a 

 marine climate tells on that species in its superior solidity and 

 colouring. 



Crossing, to the eastward, the valley of Assam, and arriving 

 at the group of mountains south and east of the Berhampooter 

 river, we meet some fine forms in C. eximius, Mouss., Pearsoni, 

 and zebrinus, nobis, Stenomphalus, and Bensoni*, Pfeiffer; C. 



* The habitat of this shell was unknown to Pfeiffer. I have the ordinary 

 variety from the northern base of the Khasya hills, near Gowaiatty, in 

 the Assam valley. The specimens were kindly sent to me by Captain 



