Mr. W. H. Benson on Clostophis and Rhiostoma. 95 



phyllum and EUisia (Gsertu. pi. 110 & 184), the placenta grows 

 round the seeds, which it soon encloses entirely, and fills the 

 cell of the fruit. When the capsule bursts, this looks like an 

 internal coccus, assuming the appearance of a resilient endocarp, 

 which opens into two valves corresponding with those of the 

 capsule; and upon the inner surface of these placentary valves 

 the seeds are parietally affixed. 



[To be continued.] 



IX. — On Clostophis and Rhiostoma, new Burmese Genera of 

 Land-Shells. By W. H. Benson, Esq. 



Clostophis^, B., nov. gen. 



Testa sub-biconica ; anfractus penultimus maximus, ultimus desceu- 

 dens, solutus, subaxialis, minor ; apertura integra (specie adhue 

 cognita), dentata. 



C. Sankeyi, B., n. s. 



Testa late umbilicata, sub-biconica, Isevi, spira turrito-conica, lateri- 

 bus cavis, apice obtuse, sutura profunda ; anfractibus 5, primis 

 angustis convexiusculis, penultimo multo majore cylindrico, ultimo 

 antice rapide descendente, solute, tubuliformi, quoad peripheriam 

 antepenultimi minore ; apertura integra, subaxiali, subumbilicali, 

 valde obliqua, subcirculari, intus superne dente 1 submarginali 

 loco quasi parietali munita, peristomate tenui, expanse. 



Diam. major Ij, alt. If mill. 



Habitat prope Moulmein, ad cavernas "Farm Caves" dictas. 



I discovered this singular shell in the earth which filled the 

 cavity of a decayed specimen of Sophina schistostelis collected by 

 Major R. H. Sankey. It was accompanied by a minute and 

 new species of Hydrocena. The specimen is weathered. Not- 

 withstanding the presence of a tooth in the aperture, there is 

 little room for hesitation in referring this novel form to the 

 Cyclostomacea, wdth reference to the solute descending last 

 whorl, and to the entire subcircular aperture, the expanded 

 margin of which forbids an union with Aulopoma, from the 

 impossibility of its being furnished with a similar opcrculuni; 

 while the absence of a slit and crowning tubular process pre- 

 vents association with Rhiostoma. That the presence of a tooth 

 within the aperture does not militate against Cyclostomaceous 

 affinity is demonstrated by its occurrence in the genus Diplom- 

 inatinaf. 



* k\o)(tt6s, coiled ; o^ir, serpent. 



t In the Brazilian Cyclosloma disjunctum, Moricand, the solute last whorl 

 descends laterally, as in Aulopoma. 



