1S60.] Contributions to Indian Malacology. 121 



grouped ; or that the distinctions between the Indian areas are satis- 

 factorily explained by considering them as " streams" of generic 

 affinity radiating from that island. So far as our present knowledge 

 extends we are inclined to look upon the distinction as consisting 

 mainly in the more favorable conditions for land shells generally in 

 the moist countries of the Himalayas and of the Burmese and Malay 

 peninsula, in the absence of shells of the Pupina and Megalomastoma 

 type in the Indian peninsula, (a circumstance doubtless connected 

 with the greater dryness of the country) and in the existence of a 

 generic centre in the island of Cejdon, characterized especially among 

 the Cyclostomacece by forms of Aulopoma and Cataulus. 



The shells described in the following pages were obtained in collec- 

 tions made by Mr. H. F. Blanford in 1857, and by Mr. W. T. 

 Blanford during a short visit in 1859. A few other forms procured 

 at the same time are also believed to be undescribed, but as they are 

 of less interest, they must await further leisure. 



Opisthostoma, gen. nov. 

 Testa operculata ? Anfractibus apicialibus obliquiter defiectis, 

 anfractu ultimo eonstricto, deinde infiato, denique sinistrorsim ascen- 

 dente, anfractibus superioribus contiguo ; apertura reversa, rotundata, 

 contiuua ; peristomate duplicato. 



1. — 0. Nilgirica, n. s. 



Testa minima, truncate pupiformis, auguste umhilicata ; spira. irre- 

 gulari, apice obtusa, obliqua, sutura profunda ; costulata, interspatiis 

 minutissime decussatis, albida, translucens. Anfractus rotundati, 5, 

 quorum duo primi obliquiter contorti ; ultimus constrictus, deinde 

 inflatus, refractus, ascendens, denique sinistrorsus, anfractum penul- 

 timum contingens. Apertura subobliqua, superne versata, orbicularis. 

 Peristoma continuum, incrassatum, duplicatum. 



Diam. maj., 1.3 m. m. 



Alt., 1.1 m. m. 



Habitat apud Pykara ad surnmos montes " Nilgiri" inter folia 

 caduca humida sylvarum. 



Of this remarkable little shell the first and only known specimens 

 were found by one of us rather more than two years since in the dead 

 leaves of one of the little thickets termed " sholas" near Pykara on 



