GIBBUS. 83 



G. OBESUS, Gibbons. PI. 17, fig. 21. 



Smooth, white, semitransparent, peristome opaque white, 

 suture linearly margined. Length, 1 inch. 



Zanzibar ; near Lake Nyassa. 



Except in size very like the preceding species, of which it may 

 be a dwarf variety. 



G. TUMIDUS, Morelet. PI. 17, fig. 19. 



White, cretaceous, smooth, under a thin, waxy yellow epider- 

 mis, partly eroded, rimately perforate, solid, suture narrowly 

 margined, columella obliquely plicate, lip somewhat thickened 

 and shortly reflected. Length, 36 mill. 



j* Hob. unknown. 



^possibly only a variety of G. ovoideus. 



G. INTERMEDIUS, Morelet. PL 17, figs. 20, 22, 23. 



Profoundly rimate, obsoletely costulate ; white ; suture im- 

 pressed, submarginate ; columella receding, plicate ; lip narrowly 

 expanded, somewhat thickened. Length, 36 mill. 



Madagascar. 



Figs. 22 and 23 represent a variety found on the island of 

 Nossi-Be, N. W. of Madagascar. 



G. LIBERIANUS, Lea. PI. 17, fig. 26. 



Rimate, finely obliquely striate, and very finely impressly 

 spirally striate, smooth, polished, suture submarginate ; hyaline 

 white. Length, 1 inch. 



Liberia. 



Bulimus pupulus, Morelet, is a synonym. The animal is grass- 

 green. 



G. INSTGNIS, Pfr. Pi. 17, fig. 16. 



Shortly rimate, very thin, pellucid, decussated by very slight 

 striae ; columella receding, dentate-plicate, lip thin, expanded. 



Length, 37 mill. 



Gaboon, Africa. 

 G. MARTENsr, E. A. Smith. PL 17, fig. 17. 



Like the preceding species in general form, but is perforated, 

 somewhat heavier, columella not plicate, longitudinal striae 

 stronger, the spiral striae only visible in their interstices ; the 



