DESCRIPTION OF PLATE I. 



Pachylabra polita (Deshayes). 

 Fig. 1. Large shell from Cambodia. Half natural size. 

 Fig. 2. Type — specimen of var. compressus Nevill, from 

 Cambodia. Half natural size. 



Pachylabra conica (Gray). 

 Fig. 3. Shell from Pegu, Burma. Two-thirds natural size. 



Pachylabra gracilis (Lea). 

 Fig. 4. Shell from Siam. Natural size. 



Pachylabra turbinis (Lea). 

 Fig. 5. Type-specimen of var. subglohosa, Nevill. ?From 

 Siam. Half natural size. 

 Pachylabra turbinis var. dalyi (Blanford). 

 Fig. 6. Large shell from Pitsanuloke, Siam. Half natural 

 size. 

 Pachylabra turbinis var. subampullacea, Nevill. 

 Fig. 7. Large shell from Lampam, Patalung, Siam. Half 

 natural size. 

 Pachylabra turbinis var. lacustris, no v. 

 Fig. 8. Type-specimen from the Tale Sap, near Lampam, 

 Siam. Half natural size. 



Pachylabra angelica, sp. nov. 

 Figs. 9, 10. Type-specimens from Bangkok. Half natural 

 size. 



Pachylabra begini (Morlet.) 

 Fig. 11. Shell from Korat district. Two-thirds natural 

 size. 



Pachylabra pesmei (Morlet). 

 Fig. 12. Shell from Koh Samesan off C. Liant, Gulf of Siam 

 Natural size. 



JOURN. NAT. HIST. SOC. SIAM, VOL. IV. 



