EXPLANATION OF PLATE XX. 



Freshwater Shells from Mesopotamia. 



Melanopsis subtingitana, sp. nov. 



Fig. 1. — Type-specimen (? subfossil), probably from Basra, x2. 

 „ 2. — Subfossil shell from lacustrine deposit at Nasariyeb, x2. 



Limnaea tenera (Parreyss), Mousson. 



., 3. — A series of subfossil shells from paludine deposit at Nasariyeh, 



x2. 



Limnaea feregriformis, Locard. 

 „ 4. — Subfossil shell from lacustrine deposit at Nasariyeh, X 2. 



Limnaea suhpersica, Locard. 

 „ 5. — Subfossil shell from the same deposit, x2. 



BulUnus contortus (Michaud). 



,, 6. — A series of shells from Nasariyeh, x2. a — c, shells from 

 lacustrine deposit : d, shell from bank of Euphrates. 



Fius. T-IL — Ventral view (further enlarged but not drawn to scale) 

 of a series of shells from Nasariyeh and Samara. Figs. 

 7, 8, shells from bed of old tank at Samara ; figs. 9, 10 

 (66, 6c), from lacustrine deposit at Nasariyeh ; fig. 11 {Qxl), 

 from bank of Euphrates at same place. 



CorhuJa [Erodomi) mesnpoUmiica, sp. nov. 



Fig. 12. — Eight valve of type-specimen (subfossil) from lacustrine 

 deposit at Nasariyeh, x4. 



,, 12a. — Hinge of same, further enlarged. 



„ 13. — ^Left valve of type-specimen, x4. 



,, 13a. — Hinge of same, further enlarged. 



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