142 Contributions to Indian Malacology. [No. 2, 



8. ALTOiEUS Theobaldi, 11. s. 



Testa aperte umbilicata, conoideo-depressa, corneo-albida, translu- 

 cens, costulis elevatis, sinuatis, remotis ornata, inter costulas stria- 

 tula. Spira depresso-conica, apice obtusula, sutura impressa. An- 

 fractus 3f convexi, ultimus ad latus mediocriter tumidus, ibidem con- 

 fertissime eostulatus. Spatium constrictum longum, striatulum, 

 medio tumidum. Tubulum suturale mediocre, i peripheriae subag- 

 quans. Apertura obliqua, expandens, circularis ; peristoma ad anfrac- 

 tum penultimum breviter interruptum, marginibus eallo junctis, du- 

 plex ; externo expansulo, interno breviter porrecto. Operc : eorneum, 

 multispirum, externe perconcavum, nucleo centrali interno promi- 

 nente papillari. 



mm. inch 



Diam, maj. 4 or 0.16 



Do. min. 3f 0.13 



Alt. 2| 0.1 



Ap. diam. li 0.05 



Hab. cum A. bebeti in montibus Khasi, teste W. Theobald, Jun. 



I received two specimens of this species from Mr. Theobald as 

 A. liebes, Bens, of which they were supposed to be young shells. 

 They, however, prove, on closer examination, to be fully grown and 

 distinct, the slight swelling in the centre of the constriction con- 

 trasting strongly with the high recurved ridge in A. liebes. This 

 alone would shew the present to be a different species, but it is also 

 distinguished by its lower spire, narrower umbilicus, smaller size, and 

 thinner and interrupted peristome, the last character not occurring 

 in any other species of the genus. The well-marked distant costu- 

 lation of the upper whorls of A. Theobaldi is entirely wanting in A. 

 liebes. The operculum of the latter does not appear to have been 

 described. A single specimen in my possession is dark horny, indis- 

 tinctly multispiral, extremely concave in front, and convex, almost 

 conical, behind, and deficient in the central internal boss so promi- 

 nent in most Alyccei. 



Although there is a swelling in the centre of the constriction in 

 A. Theobaldi, it does not amount to a marked ridge, such as charac- 

 terizes the typical forms of tbe section Charax of Mr. Benson, e. g. 

 A. stylifer, B. It is consecpiently not clear whether this species 

 should be classed with the members of that section, or with those of 



