1865.] Contributions to Indian Malacology. 93 



in form to the Cambodia H. repanda, Pfr., and may perhaps be 

 identical. 



It will be seen how variable the forms are. The spire varies from 

 flat to almost bell-shaped, the periphery from sharply keeled to angu- 

 late, the whorls from subconvex to flat or nearly so ; nor is there great- 

 er constancy in the form of the mouth, the sculpture, the epidermis, 

 or the breadth of the umbilicus. Distinct as many of the varieties 

 appear to be, they all pass gradually into each other, and with the 

 exceptions already described, I believe all the forms are most safely 

 classed as varieties of one species. Whether this should be called 

 rotatoria or tapeina is difficult to say, without more precise acquaint- 

 ance with the types of those shells.* 



Not far from the tapeina group must be classed H. castra, Bens., 

 which, despite its thin horny shell and sharp peristome, is not a 

 Nanina, but a true Helix. It occurs throughout the Arakan hills, 

 wherever I have searched, but is everywhere scarce. It has the 

 widest range in the Indian area of any known Helix, being found in 

 the Himalayas, in Orissa, in Ceylon, and throughout Burma as far 

 south as the Tenasserim provinces. 



H. climacterica, Bens, is very probably a Nanina, but I have not 

 had an oj>portunity of observing the animal. The shell was found by 

 Captain Ingram on the road from Prome to Tongoop, and I found it 

 again in the hills, at the southern extremity of the Henzada district, 

 and in Bassein. It occurred also in Long island, in the Bassein river. 

 It is much smaller in general than the typical Rhasi hill shell ; I 

 possess specimens, apparently fully grown, but measuring only 13 or 

 14 millemetres in their major diameter. 



H. hariola, Bens, is a true Helix, and is found chiefly on trees near 

 Thayet Myo and Prome. It is a rare shell. Near Ava it is replaced 

 by a large sharply carinate form, which I found abundant at Thinga- 

 dan, on the Irawady, about 80 miles north of Mandele. This shell so 

 closely resembles H. capitium, Bens., that I am much disposed to 

 consider them identical, a view in which Mr. Benson, however, does 

 not agree. At Puppa hill, near Pagan, already referred to as the 



* Mr. Benson, to whom I sent specimens, considers all the forms above men- 

 tioned to be varieties of rotatoria, but some, especially that from the Tsagain 

 hills, appear to me to be at least as nearly allied to twpeina. 



13 



