EXPLANATION OF PLATE Tr: 
FRESHWATER MOLLUSCA OF BALUCHISTAN AND SEISTAN. 
The natural size of the shells is indicated by vertical or trans- 
verse lines. 
Amnicola (Alocinma) sistanica, subgen. et sp. nov. 
Fics. 1-4.—Shells from Seistan, illustrating variations in 
form. 
Fic. 5.—Operculum as seen from within (X about 10). 
Melanoides pyramis var. flavida (Nevill). 
Fic. 6.— Animal removed from shell (xX 2). 
Melanoides scabra var. elegans (Hutton). 
Fic. 7.—Shell from Sunderbans, Bengal. 
Melanopsis deserticola, sp. nov. 
Fic. 8.—Type-specimen from Kaindak, Persian Baluchistan. 
Lamellidens marginalis, subsp. rhadinaeus, subsp. nov. 
Fic. 9.—Young shell of phase B from a pool in the desert 
near Nasratabad, Seistan. 
,, 10.—Young shell of phase A from the Hamun-i-Helmand 
near Lab-i-Baring, Seistan. 
Lamellidens marginalis var. corrianus (Lea). 
Fic. 11.—Young shell from a pond on the Calcutta Maidan. 
