the Cyclostomacea of Eastern Asia, 463 



city, — all which contrast strongly with the polished unbroken 

 surface and delicate translucent shells of the Pupina group. 

 But, as above mentioned, the genus Raphaulus shows, in some 

 of these characters, a tendency to a passage. 



22. PoMATiAS, Studer. 



Two species of Indian shells have been described by Mr. Ben- 

 son, and attributed to this South-European genus, viz. : — 



P. Himalaya, Bens., from near Barjiling. 



P. [Bulimus] pleurophorus, Bens. Khasi Hills. 



A third species has recently been obtained by Mr. Theobald 

 from Arakan. 



These species agree well in general form and in sculpture 

 with the European members of the genus. Some slight differ- 

 ences, however, in the characters of the peristome and of the 

 operculum may be sufficient to entitle the Indian forms to sec- 

 tional or even subgeneric distinction. 



23. Hydrocena, Parreyss. 



Several minute forms from the Khasi Hills and Burma have 

 been described by Mr. Benson as belonging to this genus. They, 

 however, prove, on examination of the animal and operculum, 

 to differ so widely from the type, that I propose to distinguish 

 them as a new genus, probably belonging to a distinct family. 



Georissa, nov. gen. 



Testa imperforata v. vix perforata, minima, conica, succinea v, 

 rubella, plerumque spiraliter sulcata v. striata. 



Operc. semiovale, sine ullo vestigio structuree spiraUs, excentrice 

 striatum, testaceum, transparens. 



Animal parvum, lobis hemisphaericis in loco tentaculorum munitum. 

 Oculi normales. Pes brevis, rotundatus. 



Type, G. pyxis, Bens., sp. 



The species of which I have examined the animal is the little 

 G. pyxis, Bens., from the neighbourhood of Thayet Myo in Pegu, 

 where it abounds, adhering to limestone rocks. It is found, in 

 similar localities, throughout the region of Pegu west of the 

 Irrawaddy. All the other species, so far as I am aware, also 

 occur in the neighbourhood of limestone ; G. frustillum, Bens., 

 from the vicinity of Ava, certainly does so. The operculum of 

 the last-mentioned species I have also examined, and found it to 

 be precisely similar to that of G. pyxis. 



The other species which may be referred to this genus are 



G. illex*, Bens. Tenasserim. 



* The operculum of Hydrocena illex is described as paucispiral. In 

 these very minute shells it is so difficult to examine the operciila, that very 



