1910.] N. Annandale : Species of Phlebotomus. 43 



never has more than one joint, but is often elbowed; it arises from 

 a subgenital plate, which represents the last somite of the abdomen. 

 This subgenital plate, which is highly developed in some Psychodidse, 

 is very inconspicuous in Phlebotomus , owing rather to its mem- 

 branous nature than to its small size. In dried specimens it dis- 

 appears almost completely. The intromittent organ, which lies 

 between the two intermediate appendages, consists of a pair of 

 slender, compressed chitinous valves, between which a pair of long, 

 slender, chitinous filaments can be protruded. 



Head— 



The head in Phlebotomus is small and round but the anterior 

 part is produced into a more or less cylindrical rostrum, which 

 overhangs the mouth parts above. The eyes are large, invariably 

 dark in colour and more or less emarginate opi)osite the base of 

 the antennae. The antennae are long and filiform, having nor- 

 mally sixteen joints, two of which form the scape. They show 

 great individual variation as regards the proportions of the joints 

 and also differ as regards the exact outline of the last few distal 

 joints in the two sexes. The sexual differences are, however, 

 small. The palpi are generally stated to have four joints. In 

 fresh specimens, however, a minute basal joint can sometimes be 

 distinguished. This joint is often difficult to see and appears to 

 be imperfectly separated from the others. Including it the number 

 of the joints is five. 



For an account of the mouth parts Grassi may be consulted. 

 They do not appear to present features of merely diagnostic 

 interest and closely resemble those of Culex in general structure. 



THE INDIAN SPECIES OF VHLE'BOTOMUS. 



Table of the Indian species of Phlebotomus. 



1. Length 2 mm. Dorsum of thorax dark, sides 



yellowish. Wing with the posterior border 

 much more strongly arched than the anterior ; 

 the anterior branch of the second longitu- 

 dinal vein longer than either the distance 

 between the two forks of the vein or that 

 between the posterior fork and the mid 

 cross-vein; the latter distance shorter than 

 that between the two forks . . . . P. ay^entipes. 



2. Length yS75 ^^m. Colour an almost uni- 



form golden grey. Wing with the posterior 

 border much more strongly arched than the 

 anterior ; the anterior branch of the second 

 vein longer than either the distance between 

 the two forks of the vein or that bi-tween the 

 posterior fork and the mid cross-vein ; the 

 distance between the two forks shorter than 



