222 



H. GRAHAM CANNON 



are riura))erod in Text-fig. 2 from behind forwards. No. 1 in 

 very long, reaching back to the hind end of the body, and is 

 beset with long hairs. No. 2 is much shorter and ends in 

 a sniiih hook, and possesses a comb-hke row of minute closely- 

 set hairs over a little more than half its length on one side. 

 Nos. 3, 5, G, and 7 really form a series. They are short stout 

 setae ending in a brush-like tuft of hairs. No. 4 differs slightly 

 from th(^m in being shorter but terminating in a long thick 



Text-fig. 2. 



Gnathobase of second trunk-liinb of S i m o c e p h a hi s v c t « 1 u s 

 (for explanation see text). 



hair projecting beyond the rest. Lilljeborg (13) does not 

 figure this difference. Nos. 8, 9, and 10 have the form of for- 

 wardly projecting combs. No. 8 is usually bent at an angle at 

 about its middle point, while Nos. 9 and 10 are curved. The 

 hairs on No. 8, which only occur on its distal half, are very 

 fine and regular, and are about tmce as closely set as those 

 on Nos. 9 and 10, which occur along the whole length of the 

 setae. During the movement of the second trunk-limb out- 

 wards and forward the gnathobase also moves upwards so that 

 its three anterior setae comb the side of the tip of the labrum. 

 When the limb is in its most forward position these three setae 

 have passed across the labrum on to the maxillae. 



Each maxilla is armed with three setae which do not point 

 dorsally as figured by Cunnington (5), but point forwards along 



