Mr. "W. II . Benson on new svecies of Cyclostoma. 187 



rata punctata et lineata, plerumque fascia unica nigrescente con- 

 spicua ad periphseriam cincta ; spira conoidea, acuta ; anfractibus 

 5 convexiusculis, primis oblique striatis, ultimi peripheeria obsolete 

 angulata ; apertura ampla, circulari, subverticali, marginibus callo 

 tenui junctis ; peristomate expanso, sub-planato-reflexo ; umbilico 

 pervio. Operculo tenui, corneo, multispirato. 



Diam. maj. 30, minor 23, axis 19 mill. ; sp. major. 



Diam. maj. 24, minor 19, axis 14^ mill. ; sp. minor. 



Hab. ad Insulam Penang. Teste Cantor. 



I have thought it advisable to introduce this species here, in 

 order that it may accompany the three preceding species and that 

 immediately following, which, equally with it, belong to the same 

 division of Pfeiffer's subgenus Cyclophorus. The shell forms part 

 of a collection of Penang and Malay species, of which "Dr. Cantor 

 entrusted the publication to me, together with some interesting 

 drawings of the inhabiting mollusks, which, I hope, will now 

 shortly see the light. 



5. C. porphyriticum, nobis, n. s. 



Testa mediocriter umbilicata, depresso-conoidea, tenui, striis confer- 

 tissimis distinctis, elevatis, subundulatis, spiraliter munita, albida, 

 superne saturate castaneo, subtus pallidiore ornata, maculis angu- 

 latis, circa suturam majoribus, conspersa, fasciis saturatis duabus 

 albo-articulatis, altera ad periphseriam, altera inferiori cincta ; spira 

 brevi, apice acuto, sutura vix distincta ; anfractibus 4£ planulatis, 

 ultimo angulato, subtus planiusculo ; apertura ampla, ovato-circu- 

 lari, livide albida, peristomate tenui, expanso, reflexo, marginibus 

 callo tenui junctis, conniventibus, columellari angustato, leviter 

 emarginato. 



Diam. major 31, minor 24y, axis 18 mill. 



Hab. in India Orientali. 



Allied to C. aquilum, Sow., but differing in tenuity, depressed 

 form, keel, and sculpture. I received this shell from Sowerby, 

 in 1834, as one of the varieties of C. Perdioc ; however, the com- 

 pressed form of the shell, its sharply sculptured stria?, and the 

 characters of the aperture sufficiently justify its separation. In 

 Sowerby's fig. 127, and in Krister's fig. 7. pi. 8, the columellar 

 lip is expanded above the umbilicus, instead of being narrow and 

 connivent with the superior margin. Sowerby omits any notice 

 of the sculpture, and that which is ascribed to it by Pfeiffer is of 

 a very different character. In form C. porphyriticum somewhat 

 approaches C. zebrinum, mihi, but differs in sculpture, markings, 

 less produced spire, less flattened underside, much wider umbi- 

 licus, and in the absence of the peculiar hispid epidermis which 

 clothes that rare species. Sowerby, in his description of C. ze- 

 brinum, notes the umbilicus as moderate. In my original de- 

 scription (Journ. Asiat. Soc. Calcutta for 1836), I described it as 



