62 RISSOID^. 



Genus PACHYDROBIA, Crosse mid Fischer. 



J. de C. XXIV, 1876, type P. paradoxa, Cr. and F. ; genus of Fam. 

 RissoidcB, fide Martens; fide Poirier, J. de C. 1881, belongs to the Sydro- 

 hince, next allied to G^illia. 



1. Pachydrobia parva. 



Pacliycbilus parvus. Lea, P. Ac. Nat. Sci. PMlad. I III, 1856, Siam ; = 

 Melania crassilahrum. Peeve, Icon. 1860; = Paludomus cyanostonius, 

 Morelet, J. de C. 1864, Siam. 



4 Cambodia; ex c. A. Morelet, Esq. 



2. Pachydrobia paradoxa. 



Pachydrobia paradoxa, Crosse and Fischer, J. de C, 1876, Camhodia. 



1 Locality ? ; ex " Linnsea." 



Genns HEMISTOMIA, Crosse. 

 J. de C. 1872, type Semistomia caledonica, Crosse. 



1. Hemistomia caledonica. 



Hemistomia Caledonica, Crosse, J. de C. 1872, near Noumea, long. 2k, dlam. 

 f mil. 



2 New Caledonia J ex c. P. Bouvier, Esq. 



Genus TRICULA, Benson. 



Calcutta J. Nat. Hist. 1842, type T. montana, Benson ; fide Stimpson, 

 StoliczTca and Blanford, belongs to Fam. Pissoidce. 



1. Tricula montana. 



Tricula montana, Benson, Calc. J. Nat. Sist. 1842, and Ann. Mag. 1862, 

 Bhimthal, at 4,000 ft., Kumaon ; Con. Indica, pi. 155, fig. 1. 



10 Nynee Thai ; coll. Dr. F. Stoliczka. 

 7 Bhimthal [? typical] ; ex c. Asiatic Society, Bengal. 



var. curta, nov. 



2 Jhiri Valley, at 3,000 feet [N. Cachar] j coll. Colonel H. H. Godwin- 

 Austen. 



Genus BAIKALIA, von Martens \_emend.']. 



Jahrb. Mai. Ges. 1876, for Limnorea,DybotvsM, 1878 \_not of Leach, <^c.)'\ 

 type B. angarensis, Gerst. ; sect. = LiobaiJcalia, Martens, Jahrb. 1876, 

 type B. stiedae, Dyb. ; sect, = Lyboivskia, Dall, P. B, S. 1876, type B. 

 ciliata, Dyb, 



