CLAUSILIID^E. 301 



it resembles Blanford's H. Bensonianum from near Ava, but 

 differs in the shape of the last whorl, and in the dentition of 

 the aperture. The latter is in both species almost vertical, not 

 turned entirely upwards, as in the type of the genus, H. tubi- 

 ferum. As regards form, the present species indicates still more 

 distinctly the affinities of Hypselostoma to Pupa, than does 

 H. Bensonianum." (Stoliczka.) 



In addition to the fore-mentioned differentiating characters 

 H. dayanum may at once be distinguished by its smaller size, 

 being the smallest member of the group. It appears to be a rare 

 species and I have not seen any specimens. 



Family CLAUSILIID^. 



Genus CLAUSILIA, Draparnaud. 



Clauxilia, Draparuaud, Hist. Nat. Moll. Terr. Fluv. France, 1805, 



p. 24, 29 ; Stoliczka, J. A. S. B. xl, 1871, p. 173 (anatomy) ; 

 oettger, Palaxmtogr. 3rd Suppl. 1877 ; ibid., 17 & 18 Ber. 

 Offenbacher Ver. Naturw. 1878, Mitt. p. 18 ; Wiegmann, Jahrb. 

 Deuts. Malak. Ges. v, 1878, p. 157 (anatomy). 



TYPE, (first species) Turbo Udens, Linn. 



Ranye. India, Ceylon and Nicobars, Farther India, China, 

 Japan, Malay Archipelago ; Asia Minor ; Northern Africa, 

 Madeira; Europe; South America and Porto Rico. 



Shell sinistral in the great majority of species (invariably so in 

 the Indian forms), cylindrical or fusiform, more or less solid, 

 usually striated or ribbed transversely, generally more strongly so 

 behind the aperture ; spire usually turreted, with acute or obtuse 

 apex; aperture small, usually pear-shaped, sometimes subquadrate- 

 ovate, sometimes with a sinus at the upper angle, provided with 

 two spiral entering folds usually on the parietal lip, the lower 

 sometimes on the outer lip, both continued internally as far as the 

 seat of attachment of the pedicle of the clausilium ; the upper 

 follows the spiral convolution of the columella and becomes the 

 columellar fold (inferior lamella of Pfeiffer) ; a second fold further 

 back, known as the subcolumellar (columellar of Eossmassler) 

 fold, its termination sometimes visible from the aperture ; these 

 two folds form a long flexuous groove, slightly dilated towards 

 the aperture, but further down becoming again contracted. In 

 addition there is a curved flexuous, tongue- shaped, elastic plate, 

 known as the clausilium, which higher up becomes contracted 

 into a narrow twisted pedicle, its distal extremity attached to the 

 inner shell-wall, between the distal extremities of the columellar 

 and subcolumellar folds, the groove between these, lower down, 

 receiving the clausilium as it is pushed to one side by the animal's 

 extrusion. In. addition to these processes there are a varying 



