478 JOURNAL, BOMBAY NATURAL HIST. SOCIETY, Vol. XXI. 



that in some species the sculpture of the enclosed area at ther 



base of the median segment is subject to considerable variation. 



Key to the Indian species of Cerceris. 



Females. 



5 $ . Cheeks with a stout spine .... 2 



Cheeks without a spine . . . . . . . . 4 



Clypeus flat ; pygidial area much narrowed to 

 the apex ; the spine on the cheeks very long 

 and stout . . . . . . . . . . C. inexorabilis Turn, 



Clypeus not flat ; pygidial area only slightly 

 narrowed to the apex ; the spine on the 

 cheeks short or of moderate length . . . . 3 



Clypeus slightly concave ; the spine on the 

 cheeks moderately long 



1. 



2. 



Clypeus slightly convex ; the spine on the 

 cheeks short 



4. Sides of ventral segments 3-5 with erect plates ; 



fifth ventral segment recurved at the apex, 

 with a triangular tooth in the middle 

 Ventral segments without lateral erect plates ; 

 fifth ventral segment not recurved and without 

 a median tooth . . 



5. Fifth ventral segment produced at each of the 



apical angles into a stout, blunt tooth 



Fifth ventral segment not produced into a 

 tooth at the angles 



6. Second ventral segment with a raised area at the 



base 

 Second ventral segment without [a. raised area 

 at the base 



7. Clypeus with a free lamina springing from the 



base 



Clypeus without a free .lamina or with the ex- 

 treme apical margin only free 



8. Mesopleurse tuberculate or spinose 

 Mesopleurse without tubercles . . 



9. Mesopleurse with two well defined tubercles 

 Mesopleurse with only one well defined tubercle. 



C. ephippium 

 Turn. 



C. Jletcheri Turn. 

 C. mastogaster Sm 



C. funerea Costa, 

 var pallidopicta 

 Bad. 



6 



30 



C. violaceipennis 

 Cam. 



9 

 12 

 10 

 11 



