56 PROCEEDINGS OF TBTE MALACOLOGICAL SOCIETY. 



ON A NEW SPECIES OF HELIX FROM THE KIIASI HILLS. 



By John H. Ponsonbt, F.Z.S., etc. 



Read January UtJi, 1894. 



Nahtna (Sessaea) episema, n.sp. 



Testa convexo depressa, tenuis, fiisco-coniea ; anfr. 71 rcgulaiitcr 

 accrescentes, sutura sat profunda discreti ; subtus convexior, in 

 umbilicum profunde excavatum iniporvium descendens ; apex et anfr. 

 primus la>ves, relicpii us([ue ad basin striis crebris elevatis oblique 

 sculpti, striis ad periphcriani obtuse carinatam hand interruptis, scd 

 infra scnsim minus validis ; perist. tenue, vix reflexiuscuhim, flexuo- 

 sum, intus albo limbatum, trilatcrale ; margines distantes; dexter, 

 ab insertione curvatim descendens, apud oariuam subito et pajne 

 rectangulatim deflexus (in medio hujus lateris dento erecto crasso 

 intus prolongato extus couspicuo munitus) ; deinde, interum pa>ne 

 rectangulatim procedens, paullo anti insertionem laminam spiralem, 

 intrantem, extus conspicuam emittens. Diam. max. 15, min. 14 mm.; 

 alt. 8-5 mm. Ilab. — Khasi Hills, Indise Orient. 



Nanina [Sessara) episema, n.sp. 



This remarkable sbell, of which Mr. Hugh Fulton received eight 

 or nine specimens from the locality named, calls to mind, from tlie 

 general form and the costulation of the upper surface, certain species 

 of Microcystis — e.g. M. ornatissime, Bens. The apex and the first 

 whorl are smooth, or nearly so, the remaining six, which are separated 

 by a channelled suture, being regularly sculptured with raised oblique 

 costulations, which cross the angulated periphery, becoming fainter as 

 they approach the deeply and suddenly excavated base. The outer 

 lip, at first descending in a curve, is suddenly defiected almost at 

 right angles. In the middle of this second side the thin white inner 

 margin of the peristome (the border of which is scarcely refiected) 

 is abruptly elevated into an erect obtuse tooth, which approaches 

 to within 1 mm. of the opposite basal whorl. This tooth is slightly 

 prolonged inwards and is plainly visible from without. The outer 

 lip, turning ofP again almost at right angles, emits, just before 

 entering the base, a spiral lamina, which, entering and encircling 

 the umbilical region, appears from without as a ring of callus. It 

 should be noted that the comparative prominence of the tooth on the 

 outer lip and of the basal lamina varies somewhat in the different 

 specimens, the latter character being in some almost obsolete. Sir. 

 Fulton has presented the type specimen to the Natural History 

 Museum. 



