Mr. W. H. Benson on new species of Paludomus. 495 



of the marine genus PurpurUy and the animal (of which I was, 

 in the early part of 1853, kindly furnished with an interesting 

 sketch by Mr. Frederick Layard of the Ceylon Civil Service) 

 fully bears out the separation of the shell. It may, indeed, be a 

 question whether Tanalia belongs to the Paludomida at all. On 

 the other hand, the subspiral operculum of Philopotamis, Lay., 

 seems rather to indicate its place to be among the Melaniadce, 

 from the spiral and subspiral types of which family it differs in 

 having the nucleus removed towards the right side of the base ; 

 the formation of the shell alone exhibiting a relation to the 

 Paludomida. The subspiral opercula of the American forms 

 Anculosa, Gijrostoma, and Amnicolttj all point rather to the Mela- 

 niada than to Paludomus. Reeve, who was right in his conjec- 

 ture respecting the affinity of Melania obesa, Ph., to Paludomus, 

 has erred respecting that of M. Griineri, Ph., inasmuch as, ac- 

 cording to the assertion of Philippi, its operculum consists of six 

 spiral turns. 



I may add the following characters of the restricted genus 

 from my inedited paper above referred to. 



Paludomus, Swainson. 



Testa plerumque imperforata, globoso-ovata, ovato-oblonga, vel 

 ovato-acuta, fere solida, glabra, spiraliter sulcata, vel lirata, inter- 

 dum spinuloso-costata, epidermide cornea induta ; apertura sub- 

 verticali, ovato-acuta, callo parietali munita, margine columellari 

 crasso, arcuato, basali integro, interdum subeffuso. 



Operculo corneo, concave ; nucleo subspirali insulari, submediano, 

 ad sinistram sito, striis lamellatis concentricis partem majorem 

 disci usurpantibus, circumdato. 



The genus occurs in Ceylon, Southern India, Gangetic India 

 to the eastward of a line drawn from Sikkim to the mouth of 

 the Hooghly, in the Burhampooter in Assam, and in the hill- 

 streams which flow into that river from the eastward, in Burmah, 

 and Sumatra. 



I possess from North-eastern India, besides P» conica, Gray, 

 lutosa, Soul., Stephanus, nobis, and Paludinoides, Reeve, four 

 other species which I cannot, with any degree of certainty, refer 

 to published descriptions ; and from Southern India two species 

 in addition to P. obesa, Ph. 



I may remark cursorily that Swainson's name having reference 

 to the dwelling -place of the genus in marshes, the specific names 

 ought to bear a feminine termination. 



I. Paludomus labiosa, nobis, n. s. 



Testa ovato-globosa, Iseviuscula, oblique tenuiter et obsolete spiraliter 

 striata, versus suturam 2-3-sulcata, luteo-olivacea, nigrescenti- 



