Mr. W. II. Benson on new sjjecies o/" Paludomus. 495 



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

 in the early ])art 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 Tannlia belongs to the Paludomidce at all. On 

 the other hand, the subspiral operculum of F/iilopotamis, Lay., 

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

 from the spiral and subspiral ty])es 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 

 Paludomidce. The subspiral opercula of the American forms 

 Anculosa, Gyrostoma , and Amnicola, 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, cpidermide cornea iuduta ; apertura sub- 

 verticaii, ovato-acuta, callo parietali munita, margiue columellari 

 crasso, arcuate, basali integro, interdum subefFuso. 



Operculo corueo, concave ; nucleo subspirali insulari, submediano, 

 ad sinistram site, striis laracllatis 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 Ilooghly, in the Burhampooter in Assam, and in the hill- 

 streams which flow into that hxer from the eastward, in Burmab, 

 and Sumatra. 



I possess from North-easteni India, besides P. conica, Gray, 

 lutosa, Soul., Slephanus, 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. 



1. Paludomus lahiosa, nobis, n. s. 



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

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



