250 Mr. W. H. Benson on neiv species of Burmese Helices. 



elevato, obtuso, sutura profunda ; anfractibus 6^ angustis, lente 

 accrescentibus, ultimo superiie subangulato, subtiis convexiusculo ; 

 apertura sub-anguste liinata, obliqua ; peristomate acuto, leviter 

 sinuato, margine columellari brevissimo, basalique expansiusculo, 

 dextro erenulato. 



Diam. major 14, minor 12, axis 5 mill. 



Ilah. ad Phie Than vallis Tenasserim. Teste W. Theobald. 



The sculpture of this discoid species is very elaborate, and 

 strongly pronounced in proportion to the size of the shell, pre- 

 senting a very beautiful appearance under the lens. The ends 

 of the spiral lirse give a scalloped edge to the outer lip. 



3. Helix capessens, n. s., nobis. 



Testa imperforata, depresso-conoidea, superne radiatim costulato- 

 striata, subtus Iseviori, rufo-cornea ; spira subconoidea, apice ob- 

 tusiusculo, sutura impressa ; anfractibus 6^ convexiusculis, lente 

 accrescentibus, ultimo acute carinato, antice leviter depresso, subtus 

 convexiusculo, ad periomphalum excavato ; apertura transversa, 

 angusta, dentibus 3 basalibus sequalibus coarctata, margine recto, 

 obtuso, vix sinuato. 



Diam. major 9, minor 8, axis 4 mill. 



Hab. ad Maulmain. Teste W. Theobald. 



Nearly related to H, infrendens, Gould, which was found by 

 Mr. Theobald at the Rangoon Caves on the Salween River, but 

 easily distinguished by its more depressed form, keeled periphery, 

 and the more regular dentition of the basal margin. The profile 

 of the spire is less convex, and the last whorl is depressed in 

 front below the level of the keel of the penultimate whorl, 

 whereas in H. infrendens it ascends at the same part. H, capes- 

 sens forms, with H. pylaica, a notable addition to the restricted 

 section Tridopsis. 



4. Helix convallata, n. s., nobis. 



Testa Yix perforata, convexo-depressa, tenui, nitidissima, radiato- 

 striata, translucente, olivaceo-comea ; spira convexiuscula, apice 

 prominulo obtuso, sutura profunde canaliculata ; anfractibus 6 

 convexis, lente accrescentibus, prope suturam acute angulatis, ul- 

 timo rotundato, non descendente, subtus convexiusculo ; apertura 

 vix obliqua, lunata ; peristomate acuto, superne prope suturam 

 angulato, antrorsum leviter arcuato, margine columellari oblique 

 descendente, expansiusculo. 



Diam. major 14, minor 11 1^, axis vix 7 mill. Apert. lata 7, alt. 5 mill. 



Hab, ad collem Therabuin vaUis Tenasserim. Detexit W, Theobald. 



Singular among the allies of Helix vitrinoides on account of 

 the excavated canaliculate suture with a carinate margin. 



