Mr. W. H. Benson on new forms 0/ Cyclostomacea. 229 



render it easy of recognition among the depressed and widely 

 umbilicate forms of Cyclophorus. 



10. Leptopoma aspiranSj n. s. 



Testa perforata, globoso-comca, acuminata, tenui, translucente, ob- 

 lique et spiraliter exilissime striata, lineis elevatis 6" spiralibus, 

 sequidistantibus, superne munita, albido-cornea, fasciis fuscis vel 

 strigis angulatis castaneis ornata ; spira acuminato-conica, sutura 

 impressa, apice acutiusculo ; anfractibus b\ convexis, ultimo ad 

 periphseriam carinato, subtus laeviori ; apertura obliqua, subcir- 

 culari, peristomate tenui, horizontaliter breviter patente, marginibus 

 callo tenui junctis, columellari leviter emarginato. Operculo ut in 

 gen ere. 



Diam. major 11, minor 9, alt. 12 mill., apert. Q^ mill, longa. 



Hab. in valle Tenasserim. 



In form it most nearly approaches L. vitreuniy Qu., but has a 

 more acuminate spire. Its sculpture has greater resemblance to 

 that of the more globose and depressed Bornean species, L. seri- 

 catum, Pfr. The smaller specimens have a more conical and 

 trochiform appearance than the larger ones. 



11. Megalomastoma gravidum, n. s. 



Testa perforata, pupiformi, distorta, solida, laeviuscula, vix striatula, 

 fusco-albida ; spira distorto-ovata, sutura marginata, apice conoideo- 

 obtuso ; anfractibus 6 convexis, penultimo elongato supra aper- 

 turam planato, dorso gibbo, ultimo angustiori, antice subito ascen- 

 dente ; apertura leviter sursum spectante, circulari, fauce fusca, 

 peristomate albido, incrassato, superne angulato, expansiusculo, 

 reflexiusculo, intus late sulcato, turn calloso-marginato, callo inte- 

 riori dextrorsum superne angulato-sinuato, sutura canalis obsoleti 

 ad angulum anticum raro apparente. 



Long. 35 mill., diam. anfr. penult. 20 mill. 



Hab. ad Moulmein. 



In the obsolete channel, occasionally visible at the top of the 

 aperture, this shell has possibly some relation to Gould's M. sec- 

 tilabre. The indentation, invariably present in the internal callus 

 of the aperture, seems to have some reference to the obliterated 

 channel, and shows a passage to the Pupince. The form has a 

 great resemblance to that of the gigantic P. grandis, Forbes 

 {Forhesi, Pfr.), which it exceeds in size. As in that shell, the 

 great length of the penultimate whorl, above the aperture, con- 

 trasts with the shortness of the same part in the allied species 

 M. ChrysalliSy Pfr., which does not appear in the collection. 



The specimens received are weathered, and may possibly, in a 

 perfect state, exhibit an epidermis and more colour. The oper- 

 culum is, unfortunately, not forthcoming. 



