() LAND ANll FRKSllWATER 



it suhhandhiu, for I ciinnot find in my collection from the Ktiasi 

 Hills any Ulesmla that matches the type in the Henry Bluiiford 

 collection. 



Classification and Distribution. 



Mr. G. K. Gude, in the ' Fauna of British India,' puts Glessida 

 into the family Ferussacid;e (p. 373), immediately following 

 the genera CaceUoides, type acicidu, Miill., Geostdhia, type 

 ailedonica. Crosse, and balamts, lleeve, together with a new 

 species, O. bensoni (p. 375). 



With these genera I cannot agree that Glessnla has affinity ; 

 the animals are unknown, the shells very different, the 

 conditions of life and extent of range very distinct, liange is 

 an important factor in questions of this kind. C acicida is 

 I'alroarctic, spreading to the far South. Glessula is Oriental 

 and in comparison limited in its area of distrihurion. Commencing 

 with Southern India, it is absent from the N.W. Himala\a, 

 bordering on the eastern margin of the Paliearctic, coming in 

 (in Nepal?) in Sikliim and extending through the North-East 

 Himalaya, Assam with the Assam Range, and thence to Burma, 

 Cliina, "and Sumatra. AH these are forest-ciad countries with 

 considerable rainfall, or country which was once much more 

 forest-clad than at present, before man arrived to destroy the 

 ancient forests. The Khasia Hills, with the Jaintia on the East, 

 were once much more wooded than they are at present and formed 

 a tract of country of great extent. Geast Viia balanns, on the other 

 hand, may be called a desert species, standing great heat and great 

 dryness for months. A knowledge of the animal would be of 

 extreme value in every way. I cannot find that it has ever been 

 seen alive. 



I ])refer to place Glessula and its subgenera in a family of 

 its own, the Glessulidse. 



Conchologically Glessula possesses many very distinct characters. 

 It comprises shells which have the coluniellar margin abruptly trun- 

 cate at the base, which in the majority of the species forms a short 

 gutter and holds a jiart of the mantle near the right dorsal 

 margin. A well-defined division with shells of all sizes is found 

 having elongate, turi-eted, and flat-sided shells, the major diameter 

 dilfering little from that of the small aperture. Typical Bacilhim 

 ciissiaca falls under the above shell description, and I shall have to 

 refer to this subgenus — it is much more solid and opaipie, with 

 stronger regular sculpture and larger apex ; the animal (December 

 1919) still remains to be described. 



A departure from the Bacilhim type of shell character is met 

 with in Glessula tenuispira (Plate CLIX. fig. 3) ; the shell is thin, 

 transparent, more or less finely striate, the aperture larger, and 

 that and the body-whorl together are much larger than the shorter 

 spire above. 



This proportion of parts is intensified in species like Plate CLX. 

 fig. 1 hurmihnsis, fig. 2 do., fig. 3 do., fig. 4 do., fig. 5 var. maxwelli ; 

 stUl more in fig. fi batlcri, fig. 14 crassilabris, or what may be 



