1868.] Contributions to Indian Malacology, JSTo. IX. 81 



Hab. Habiang in montibns Garo (H. Godwin- Austen). 



This very interesting species differs widely in form from the only 

 previously described sinistrorse Diplommatina inhabiting India, 

 D. Huttoni, Pfr., more widely than it does from some of the reversed 

 forms met with in the Oceanic region. It shews a considerable 

 resemblance in form to D. Martensi, H. Ad., of unknown locality, 

 figured in the Proc. Zool. Soc. for 1866, but which is said by its 

 describer to belong to the section Diancta* of Martens, charac- 

 terised by a constriction at the back of the penultimate whorl. In 

 D. gibbosa as in most Indian Diplommatince, there is a slight tendency 

 to constriction in front of the penultimate whorl, to which an internal 

 rib appears to correspond, but which is covered and concealed to a 

 great extent, by the parietal callus of the peristome. 



5. D. Austeni, n. sp. PI. III. fig. 2. 



Testa dextrorsa non rimata, conico-ovata albida vel succinea. Spira 

 superne conica, non attenuata, sutura impressa, apice obtusiusculo. 

 Anfr. 6, primi 3 gradatim crescentes, confertim minute costulati, 

 ultimi laevigati vel costulis subobsoletis signati, antepenultimus major, 

 ultimus aliquando lineis subdistantibus versus aperturam signatus, 

 antice ascendens, subtus rotundatus. Apertura verticalis oblique 

 subovalis ; perist. incrassatum, mediocriter expansum, duplex, margine 

 columellari verticali, angulo aperto subtus desinente, basali rotundato, 

 plica columellari mediocri, callo parietali expanso. 



Long. 2J, diam. 1J, mill. Apertura c. perist. 1 mill, longa, intus 

 § lata. 



Hab. Cherra Poonji et Maotherichan in montibus Khasi (W. 

 Theobald et H. Godwin- Austen). 



I, some years ago, received a specimen of this species from Mr. 

 Theobald as D. polypleuris, Bens. On comparing the series of 

 Diplommatincd collected by Captain Godwin-Austen with Mr. Benson's 

 description, it is evident that the type of that species belonged to a 

 different form, found abundantly by Captain Godwin-Austen with 

 the present species on the Maotherichan ridge, part of the Northern 

 scarp of the Khasi hills, and distinguished from the present form by 



* From the description however of D. constricta, Martens, the type of 

 Diancta, that species would appear to possess peculiarities not shared by 

 Mr. Adams' species. 



