J. C. HUTSON 215 



the hind femur and hind tibia are about equal in length. The 

 femora have no spines but are covered with rather long hairs on 

 the inside. Round the tip of each tibia is a circle of small spines, 

 two of which are usuallj' longer than the others, and each tibia 

 usually has a row of small recumbent spines on each side. The 

 fore and hind tibiae have a densely sericeous area, the former in 

 a small strip on the inside near its distal end, and the latter in a 

 narrow strip along its outer side. The fore tibia has a large, 

 somewhat modified spine with a chitinous blade and some fine 

 hairs on its inner surface. This spine runs parallel to the first 

 tarsal segment which has a similar modification on its outer side. 

 This structure forms a cleaning apparatus. The middle and 

 hind tibiae each have two strong spines of unequal length, but 

 only the hind tibia has a cleaning apparatus, which is a little dif- 

 ferent from that on the fore tibia, as will be seen from a compari- 

 son of the figures. The tarsus in each leg consists of five seg- 

 ments, the first of which is much longer than any of the others 

 and is called the metatarsus. All the tarsal segments are covered 

 with closely set spines, those at the distal ends being longer than 

 the others. 



The last tarsal segment is provided with a pair of strong curved 

 claws, between which is a well developed pulvillus. On the inner 

 side of the claws near their bases there are usuallj^ two or three 

 fine hairs, one longer and stiff er than the others, while about the 

 middle of the inside of the claw there may be a small tooth. 

 These teeth occur only on the claws of the fore and middle legs 

 in these insects. 



Sensory Areas on the Antennae 

 In the females of both cyaneum and zimmermanni all the seg- 

 ments of the filament have somewhat irregularly oblong, appar- 

 ently Ixire regions lying along their inner sides when the antennae 

 are held curled forwaid. These areas appear slightly depressed 

 and usually darker than the remaining parts of the segments, 

 owing to the absence of the fine recumbent hairs with which the 

 other portions are covered. When the antennae are cleared and 

 mounted the above areas are seen to be covered with pits and 

 hairs of various sizes, probably of a sensory nature. The struc- 

 tures on the male antennae appear to be more complicated, since, 



TRANS. AM. ENT. SOC, XLV. 



