420 LAXD AND FRESHWATEK 



than either of its three allies, and differs from them also in the 

 very slight approximation of the costulation behind the constriction. 

 Almost all the species of the genus Alijcceiis are more closely aud 

 strongly marked upon the tumid port-ion of the last whorl than on 

 any other of the shell, the length of the closer ribbing and of the 

 tumidity having a general relation to that of the sutural tube." 



" Several dead specimens of A. graphicus were found at 

 Moditoung, a halting-place about 55 miles from Prome, on the 

 road across the uninhabited Arakan Toma range from that place 

 to Tongoop." 



]n William Blanford's Collection, left by him to the Trustees of 

 the Eritish Museum (Nat. Hist.), which 1 am at present engaged 

 on carefully registering, there are five examples of A. grcqihicus 

 from the above tyj)ical locality (No. 42.06.4.4). It is one of these 

 I have figured. 



I have not seen examples from the hill country on the north 

 and east, Hill Tippera being quite unknown as regards the 

 moUusea. 



With a fine series to deal with I have been able to examine very 

 closely the variation in species of the subgenus Ci/clor>/x, particu- 

 larly C graphicus, collected over a very extensive area, from 

 Arakan to the Eastern Himalaya and the Assam hill-ranges south 

 of the Brahmaputra. The result has been interesting, it has 

 defined the range of this and other species more accurately, and 

 several appear worthy of specific distinction. 



Variation in shell-character is limited in all genera. I have 

 found in Alycceus it is always constant in every sjoecimen of a 

 series from the same locality. In A. {CycJoryx) graphicus and its 

 allies I have found the most noticeable characters to be: (1) the 

 costulation ; (2) the number of costas emanating or lying opposite 

 to the sutural tube ; (3) the form of the peristome, particularly on 

 the upper inner margin close to the perforation, this being either, 

 more or less visible or completely covered with it. 



Forty years ago, considerable confusion was the result of hasty 

 determination of species of this group by those who took them up, 

 because the type-specimens in the Benson and Blanford collections 

 were not accessible and before them. Thus in Nevill's Hand-list 

 (p. 292) Alifccnis graphicus is recorded from the North Cachar 

 and Naga Hills : 40 specimens collected by myself and A. W. 

 Chennell, one of my Survey assistants, and 40 even from Darjiling 

 collected by Dr. Stoliczka, H. F. Blanford, and Colonel Main- 

 waring. Not a single typical shell from Arakan was then in the 

 Calcutta Museum. Of course all those from Darjiling are something 

 else, and even those, judging from what I collected myself and have 

 now before me, are not exactly similar to typical graphicus. 

 Among those 40 specimens in the Indian Museum from the Eastern 

 Frontier no doubt more than one species would be f(mnd. 



I have gone through all the Alycaei in my own collection which 

 had been recorded as A. graphicus or disposed of pro tern, as 



