348 Mr. W. H. Benson on an Australian Diplommatina, 



XXXI. — Notice of an Australian Diplommatina ; and Characters 

 of new East Indian Helicidse from Darjiling and Sincapore. 

 13y W. H. Benson, Esq. 



1. Helix Cycloplax, nobis, n. s. 



Testa late umbilicata, orbiculato-depressa, supra confertim et un-, 

 datim radiato-striata, striis spiralibus decussata, granulata, rufes- 

 centi-cornea, subtus leviori pallida, fascia mediaiia castanea cir- 

 cumdata ; spira convexiuscula, apice planato, sutura obsoleta, 

 demum irapressa. Anfractibus 5 planatis, ultimo subcarinato 

 (setate juvenili acute carinato) antice dilatato, prope suturam antice 

 tumidiusculo, subtus tumido. Apertura subquadrato-lunari, ob- 

 liqua, intus interdum albido sublabiata, peristomate simplici, acute, 

 margine columellari non reflexo, cum basali angulum obtusatum 

 formante. Umbilico profundo, perspective. 



Diam. major 42, minor 34, axis 1/ mill. 



Hab. ad Darjiling, Himalayse Sikkimensis montem. Teste R, Trotter. 



I am indebted for this fine and interesting shell to Mr. Robert 

 Trotter of the Bengal Civil Service, who collected it, with some 

 other new shells, during a short visit to the Sanatariuni of Dar- 

 jiling, together with a single specimen of the scarce Helix Oj-obia, 

 nobis, and some Cyclostomata previously described. Darjiling 

 is situated at an altitude of more than 7000 feet above the sea 

 level. 



The shell is nearly related to H. Oxytes, nobis, an inhabitant 

 of the mountain group south-east of the Burhampooter river, 

 but it is at once distinguished from it by its sculpture, less acute 

 periphery in the adult, the formation of the last whorl anteriorly, 

 the more tumid base, &c. H. Oxytes will be found figured in 

 Reeve^s ' Conchologia Iconica ' at plate 23 of Helix, species 734. 

 In the same and two following plates, many of the Helices de- 

 scribed in former Numbers of the * Annals ' are represented, 

 besides some other Indian species. It should be remarked, 

 however, that the figure of H. crinigera being magnified, and a 

 greater vertical depth being assigned to the mouth than it 

 actually exhibits in proportion, the shell is made to resemble 

 too closely H. Guerini, another species from the same quarter, 

 with which I compared it, but from which it is quite distinct. 

 The other figures are very characteristic, particularly those of 

 H. Ampulla, Cysis, Thyreus, solata, Cestus, and radicicola. 



2. Helix Tugurium, nobis, n. s. 



Testa perforata, depressa, tenui, supra exilissime radiatim costulato- 

 striata, striis spiralibus decussatis, subtus lajvigata, luteo-cornea, 

 spira depresso-conoidea, apice acutiuscule. Anfractibus 6 planius- 



