^yo Records of the Indian Museum. [Vol. VIII, 



Teesta, the Dikrang and now the Tsanspu have been well collected 

 in and we have a small contribution from the Subansiri. Nothing, 

 however, is known from the large valleys of Bhutan, such as the 

 Wangchu and Mochu, the Ryduk and Sankos of the plains, the 

 Monass and Barowli in the Aka Hills. The expedition there in 

 191 3- 14 brought us no knowledge of the land mollusca, and such 

 opportunities have been so often lost that years go by before they 

 come again. Surveyors have splendid opportunities for collecting 

 in every branch of Natural History, and when employed at the 

 hardest work there are hours I know which can be profitably 

 spent on wet da3^s, when clearing mountain tops. The native 

 establishment and the people of the country are always available. 

 x\ll hill men, especially Ghurkas, Lepchas and Khasis, can be made 

 keen collectors. 



vSubfamily CYCLOPHORINAE. 



Genus Raphaulus, Pfr.^ 1856. 



In 1886 the only species of this genus from Eastern Assam 

 was R. assamica, G.-A., from Brahmakund, figured in Mollusca of 

 India, plate xlvii, figs. 2, 2a, 2b. The Dihang valley, close by, 

 has now yielded no less than 6 species, together with 2 species of 

 the closely allied genus Streptanlus of Benson (1857), represented 

 by a single very variable species 5. blanfordi, a most abundant 

 shell in Sikhim and extending to the Dafla Hills on the Bast- 

 ward. 



When writing on the genus Raphaulus in 1886 (/. c, p. 196), 

 taking this into consideration and the fact that the animal of Strep- 

 taulus proved similar to that of Raphaulus , I was not inclined to 

 adopt Benson's genus. With two more species, however, present- 

 ing the same character of sutural tube as found in the Sikhim form, 

 there are better grounds now for reconsidering and distinguishing 

 the two forms and giving Streptaulus at least subgeneric rank. 

 There is quite as much difference between them, moreover, as is to 

 be found between Pterocyclos and Spiraculum and in Alycaeus and 

 Dioryx. The range of Streptaulus, so far to the Eastward, will 

 lead in all probability to other species turning up before long on 

 the head waters of the Irrawaddy, the N'mai Hka and the Hkamti 

 Ivong. 



Raphaulus assamica, G.-A. 



{Text-6g. I A.) 



Locality. — Miri Hills, two specimens {Lt. C. G. Lewis, R.E.). 



vSliell elongately cylindrical, very solid, rather closely rimate; 

 sculpture very fine and close costulation ; colour, both shells 

 bleached; spire high, sides flatly convex, apex pointed, slightly 

 inclining to the right; suture moderately impressed; whorls 6, 

 one above aperture flattened in front ; aperture circular ; peris- 

 tome much thickened, upper margin horizontal ; sutural tube well 

 developed, directed obliquely downwards, 3 mm. in length. 



