228 Mr. W. H. Beuson on new forms o/* Cyclostomacea. 



7. Pterocyclos Cetra, n. s. 



Testa late umbilicata, orbiculato-depressa, capillaceo-striatula, luteo- 

 cornea, strigis radiatis, subremotis, irregularibus, ornata ; spira 

 planata, sutura impressa, apice vix prominulo ; anfractibus 5 con- 

 vexiusculis angustis, ultimo breviter descendente ; apertura obliqua, 

 circulari, peristomate duplici, interiori continuo, breviter porrecto, 

 superiie breviter emarginato, exteriori expanse, incrassato, superne 

 lingua obtusa vix descendente, sinu proiundo ab anfractu penul- 

 timo separata, munito ; umbilico lato, non profundo, omnes an- 

 fractus exhibente, margine subangulato. Operculo ? 



Diam. major 13, minor 10, axis 4 mill. 



Hab. ad Moulmein, et in valle Tenasserim satis frequens. 



8. Cyclophorus ? scissimargo, n. s. 



Testa umbilicata, globoso-turbinata, sub epidermide cornea albida, 

 strigis distantibus angulatis picta, radiato-striata, striis exilissimis 

 et lineis elevatis remotis spiralibus, his quidem ciliatis, cancellata ; 

 spira conica, sutura profunda, apice obtusiusculo, nigrescente ; 

 anfractibus 5 convexis ; apertura obliqua, subcirculari, superne 

 leviter angulari, peristomate duplici, exteriori et interiori acutis, 

 sulco separatis, margine columellari emarginato, parietali adiiato, 

 superne breviter anguste inciso ; umbilico profundo, anguste per- 

 spectivo. Operculo ? 



Diam. major 7, minor 5|^, alt. 7 mill. 



Hab. ad Phie Than vallis Tenasserim, raro occurreus. 



This little species^ which has some affinity to C. triliratus, Pfr., 

 is singular on account of the incision which appears in the 

 parietal margin near its junction with the right lip^ a feature 

 not observed in any other species of the Cyclostomacea. It is 

 with some hesitation therefore that, in the absence of an oper- 

 culum, I refer it to Cyclophorus, although the general habit of 

 the shell bears out the location. 



9, Cyclophorus Calyx, n. s. 



Testa late umbilicata, orbiculato-depressa, radiato-striatula, albida, 

 strigis castaneis radiatis superne picta ; spira planata, sutura im- 

 pressa, apice vix prominulo ; anfractibus 4^ convexiusculis, ultimo 

 compresso, subtus, circa umbilicum minime profundum, latum, 

 angulato ; apertura obliqua, circulaid, peristomate duplici, continuo, 

 breviter adnato, externo incrassato, superne expanso, angulato. 

 Operculo 1 



Diam. major 10, minor 8, axis 3 mill. 



Hab. ad A^kaouktong, prope ripas fluminis Irawadi. 



The flattened depressed form of this shell, and the angular 

 expansion of the outer peristome at the top of the aperture, 



