100 Contributions to Indian Malacology. [No. 2, 



Gataulus. Near theTperiphery, the whorls are more numerous, hut 

 their boundaries are indistinct. 



I have in this and other papers, already given all the details con- 

 nected with the occurrence of the four species of Diplommatina as yet 

 described from Burma. The only known Helicina from Northern 

 Burma is also described above. 



Georissa. 



I have described (Ann. and Mag. Nat. Hist, for June 1864) as a 

 distinct genus, under this name, the species of Burmese and Khasi 

 shells referred to Hydrocena by Mr. Benson, both the animal and 

 operculum differing from those in that genus. But one species is 

 known to exist in Pegu, G. pyxis, Bens., and I have met with that 

 in many places west of the Irawady, from Thayet Myo to south of 

 Bassein. G. Frustrillvm, Bens., I only met with at the original local- 

 ity, Mya Leit Doung, Ava. 



It is evident that two very distinct zoological provinces exist in 

 Burma, exclusive of Martaban and Tenasserim, which form a third, 

 characterized by the appearance of several Malayan generic types, such 

 as Bajjhaidus, Hybocystis and Bhiostoma, and others apparently pecu- 

 liar, as Sophina. The two northern provinces are : 1st, Arakan, with 

 the southern part of Pegu near the sea, enjoying a very humid climate. 

 2nd, Upper Burma, with, in many parts, a very dry climate. The 

 boundary in the Irawady valley may be drawn roughly above 

 Henzada, although species belonging to each fauna, as is usually the 

 case, pass over the border. The first province, besides a considerable 

 number of peculiar species, is especially characterized by forms 

 common, on the one hand, to the Khasi hills, and even to the Hima- 

 layas, and, on the other hand, to Tenasserim. Examples of the first 

 are Helix plectostoma, Bens., H. delibrata, Bens., H. castra, Bens., &c. ; 

 of the second, Cyclophorus aurantiacus, Schum., G. speciosus, Phil., 

 Lpptopoma, aspirans, Bens., Nanina honesta, Gould, &c. In the Ava 

 province, on the other hand, the forms which have also been found in 

 India^are mostly inhabitants of the plains, such as Helix similaris, 

 Fer., Bulimus pidlus. Gray, and B. coenopictus, Hutt. The genus 

 Hypselostoma has as yet only been found within this province, or close 

 to its borders. It is rich in species of Blectopylis, and in varieties or 



