228 Mr. W. H. Benson on new forms of 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, 

 circular!, peristomate duplici, interiori continuo, breviter porrecto, 

 superne breviter emarginato, exteriori expanse, incrassato, superne 

 lingua obtusa vix descendente, sinu profundo 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 ? scissimargOj 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 adnato, 

 superne breviter anguste inciso ; umbilico profundo, anguste per- 

 spectivo. Operculo ? 



Diam. major 7, minor 5J, alt. 7 mill. 



Hab. ad Phie Than vallis Tenasserim, raro occurrens. 



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 CyclophoruSj although the general habit of 

 the shell bears out the location. 



9. Cyclophorus Calyx, n. s. ^p**^'*^^ 



ii<" 



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

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

 pressa, apice vix prominulo ; anfractibus A\ convexiusculis, ultimo 

 compresso, subtus, circa umbilicum minime profundum, latum, 

 angulato ; apertura obliqua, circular!, peristomate duplici, continuo, 

 breviter adnato, externo incrassato, superne expanso, angulato. 

 Operculo ? 



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



Hab. ad Akaouktong, 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, 



