NEW MALI.OIMIAGA. 43 



project upwards, being undoubtedly tactile organs. In 

 the case of the three genera in which the mesothorax can 

 be distinguished from the metathorax, this separation is 

 especially evident in immature specimens, as would be 

 expected in the case of a specialization by reduction. 



The legs (fig. 13, plate ii) are strong and of variable 

 length; the forelegs are the shortest and are used as foot- 

 jaws for carrying food to the mouth. When at rest the 

 forelegs project forward beneath the head. The coxa- 

 are usually short (long and projecting beyond the lateral 

 margins of the thorax in one genus) and are rarely ap- 

 pendaged. The femora vary from long, subcylindrical, 

 to short, thick, subovoid ; the tibiae are usually shorter 

 than the femora (sometimes as long, rarely longer) and 

 slender, and are armed at the distal extremity with spines 

 and sometimes, in the males, with special structures for 

 holding the female. Both femora and tibia; bear from a 

 few to many short to long hairs; sometimes series of 

 short, strong spines. The tarsi are 2 -segmented, the 

 distal segment with one (mammal-infesting forms) or two 

 (bird-infesting forms) claws, the first segment of the tar- 

 sus is short and with or without one or two small lobes ; 

 the second segment is short (family Philopteridae) or elon- 

 gate and slender (family Liotheidae) and bears a pulvillus 

 between the claws. 



Abdomen. The abdomen is flat, short, oval to long 

 and slender, often differs in the sexes, especially in the 

 shape and character of the posterior margin of the last 

 segment, and is composed of 9 (sometimes apparently 8) 

 or 10 segments. It may be almost naked or pretty thor- 

 oughly clothed with hairs, and bears almost always one 

 to several short to long hairs in the posterior lateral an- 

 gles of each segment, which angles sometimes project 

 acutely. The hairs on the dorsal surface, as on the 



