192 PROCEEDINGS OF THE MALACOLOGICAL SOCIETY. 



Superfamily YIVIPAIIOIDE^ (Gray), 1857. 

 The Viviparoids, as at present understood, constitute two families 

 — the Viviparidfe, a group common to both the old and new worlds, 

 and the Lioplacidae, at present confined to the American Province, but ' 

 formerly ranging as far west as California. Several bizarre African 

 genera customarily referred to the former group may be separable 

 into another division upon more careful study. 



Family YIVIPARID^, Gray, 1857. 



Shell large, averaging 25 ram. in altitude, conic-turbinate, sub- 

 perforate or perforate, covered with a greenish, yellowish, or brownish 

 epidermis, whorls inflated, aperture roundly ovate, and slightly 

 retracted below, but not sinuate; animal large and viviparous, 

 operculum annular, with a thickened margin and nuclear area, 

 rostrum simple and pronounced, foot quadrate and not greatly 

 produced in front of head, tentacles short and stout, the right clavate 

 in male, branchial laminae numerous, narrow or sub-linear, and 

 diverging at tips to form several rows, cervical lappets large and 

 forming trough-like ducts ; habitat lakes, marshes, and quiet streams. 



The Viviparidse common to AVesteru Europe and North America 

 belong exclusively to Viviparus or its sub-genus Callina. No member 

 of this genus occurs in the living state within the present district, 

 although, like the succeeding family, fossil forms indicate a greater 

 western extension during early Tertiary times. Two Viviparas 

 introduced by the Oriental labourers from Japan as an article of 

 food are, however, an established element of the fauna of the middle 

 California lowlands.^ While commonly classed in Paludina, Vivipara, 

 or Viviparus as it is variously called, an examination of the early 

 whorls will readily shSw that they are not congeneric with Viviparus 

 tiviparus (L.). Several years ago, in describing Vivipara Ilenzadensis 

 from India, Pilsbry- commented on certain characters which 

 peculiarized the operculum (these appear to the writer to be common 

 to the entire family), and proposed the sub-genus Idiopoma to 

 embrace cei'tain species from South-Eastern Asia, of which, however, 

 this is the only one mentioned. The species is unknown to the writer, 

 but, judging by the figure and description, doubtless groups with 

 Bengalensis, Lam., quadrata, Gray, and Japonica, v. Martens. The 

 writer would therefore extend the name to embrace the entire genus. 

 For the section represented by malleata^ Reeve, and Chineiisis, Gray, 

 in which the adolescent carina is lost early, and the shell becomes 

 decidedly globose in the adult condition, thus superficially recalling 

 Callina, the name Cipangopaludina is proposed. 



Genus Vivipaeus, Montfort. 

 Helix (sp.), Linne, 1758 (iZ". vivipara, L.) ; ' Cochlea vivipara 

 fasciata'' (not binomial), Geofi^roy, 1767; Martini's Tiansl., 1767 ; 

 Nerita (sp.), ^liiller, 1774 [N. fasciata, Miill. = H. vivipara, L.) ; 



' Hannibal, Naidihcs, xxv, p. 31, 1911. 

 2 Proe. Philad. Acad. Sci., 1901, p. 188. 



