xiv LIST OF ILLUSTRATIONS 



FIG. 



Jericho, Palestine. This bush belongs to the third 

 group of desert plants, the perennials which exist 

 above ground at all seasons ; the leaves are succulent 

 and contain great quantities of a bitter, milky sap. 

 Fragments of dead annuals may be seen. (P. A. 

 Buxton, photOj October, 1922) . . facing p. 60 



28. Graph showing the Number of Species of certain 



Families of Orthoptera present month by month in 

 Collections made at Amara, Lower Mesopotamia, 

 by W. E. Evans and the Author . . p. 66 



29. Graph similar to Fig. 28, showing the Monthly Prev- 



alence of the Fossors (" Solitary Wasps "), Bees, 

 and " four families " of Hymenoptera (i.e. Fossors, 

 True Wasps, Bees, and Ruby Wasps) at Amara p. 67 



30. Graph similar to Fig. 28, showing the Monthly Prev- 



alence of Pyrale and of Noctuid Moths and of all 

 Families of Moths except Pterophorina, Tortricina, 

 and Tineina p. 68 



31. Hairy-footed Jerboa (Jaculus jaculus) from Egypt. 



Notice the long hind-legs with reduced number of 

 toes, and the long tail with a terminal tuft of hair, 

 and the biped attitude. (Drawn from life by Miss 

 A. M. Gayton) p. 75 



32. Under-surface of Right Hind-foot of Allactaga indica 



(A), Scarturus tetradactylua (B), and Jacultts jaculus 



(C). (After R. I. Pocock) .... p. 76 



33. East African Gerbil (Taterona vicina) from East 



Africa. This animal is typical of a very large 

 number of species, most of which are found in 

 various parts of the Great Palsearctic Desert. 

 (Drawn from life by Miss A. M. Gayton) . p. 77 



34. Imperial Sandgrouse (Pterocles arenarius). (After E. C. 



Stuart Baker) .... facing p. 84 



36. Addax Antelope (Addax masomaculatus), Male, from the 



Sudan. (Drawn from life by Miss A. M. Gayton) p. 90 



36. Arabian Oryx (Oryx leucoryx), an Inhabitant of Water- 



less Sandy Desert. (Drawn from life by Miss A. M. 

 Gayton) p. 91 



37. Persian Gazelle (Oazella subgtUturosa), from Kirkuk, 



Perso-Mesopotamian frontier. The gazelles are 

 very widely distributed and the numerous species 



