472 Mr. W. H. Benson on a new Burmese Streptaxis. 



testimony to the abundance and variety of the testaceous pro- 

 ductions of that locality, and proves that it has been far from 

 exhausted by the zealous researches made by Mr. Theobald and 

 the American missionaries. Out of thirteen species sent, three 

 are undescribed ; and among the remaining ten apjiear Helix 

 pylaica, Megalomastoma gravidutn, Pupina artata, B., living ex- 

 amples of Helix Achatina, Gray, and a most beautiful specimen 

 of the rare Rhaphaulus Chrysalis, Pfr., taken in a living state 

 vrith the operculum, and with the tube in a much finer state of 

 preservation than in Mr. Theobald's weathered specimen, noted 

 in the 'Annals^ for July 1856. The costulate surface of the 

 shell exhibits a rich chestnut colour ; the broadly expanded and 

 sulcate peristome has a livid flesh-coloured tinge ; the tube and 

 back of the reflected peristome are whitish ; and the neat, con- 

 cave, five-spired, horny operculum presents a polished, resplen- 

 dent yellowish horn-coloured surface. 



1 have some I'eason for believing that most, if not all of these 

 shells, were collected in the neighbourhood of the stalactitic 

 caverns in a singularly perforated limestone hill at Damatha, 

 about twelve miles N.E. of Moulmein. Cavernous limestone in 

 warm climates seems to be generally favourable to the produc- 

 tion of land-shells of unusual forms. Of this we have examples 

 in the cavern near Turon in Cochin China, and in that of Lu- 

 bong Angin, near Sarawak in Borneo, explored by Mr. Hugh 

 Low, 



1. Streptaxis Sankeyi, B., u. s. 



Testa oblique umbilicata, rhomboideo-ovata, coufertissime costulato- 

 striata, albida ; spira vix lateral!, depresso-conoidea, sutura impressa, 

 apice obtusiusculo ; anfractibus 7, primis 5 regularibus, subpla- 

 natis, antepenultimo subacute carinato, carina subtus compressa, 



2 ultimis breviter ^eviantibus, ultimi basi circa umbilicum com- 

 pressa ; apertura obliqua, truncato-ovata, subtriangulari, lamella 1 

 parietal! submediana prominente, breviter intrante, superne callo 

 elevate ad labrum juncta, peristomate expanse, reflexo, marginibus 

 subtus convergentibus, dextro superne attenuate, sinuate. 



Diam. major 10, minor 6i, axis 7 mill. 

 Habitat prepe Meulmein. 



Nearly related to the Mergui shell, Str. exacuta, Gould, but 

 well distinguished by its more compact and upright form, open 

 umbilicus, the absence of a second angular parietal fold, the want 

 of compression of the keel on the upper side of the antepenulti- 

 mate whorl, and in having, although smaller, an additional 

 whorl. 



In Mr. Cuming's specimen of Str. exacuta the antepenultimate 

 keeled whorl suddenly increases in breadth in front, whereas in 

 Str. Sankeyi the increase is gradual and regular in that part. 



