208 Life History of Wireworms 



protrudes considerably from the anterior margin of the stipes. The 

 second segment is longer than any of the others, though not so broad as 

 the first. Two short setae are borne on the first segment, a whorl of four 

 around the apex and two at the outer margin of the second, a similar 

 whorl of four near the apex of the third, and two very short ones near 

 the middle of the fourth. At the apex a series of ten or more exceedingly 

 minute short bristles are present, which must make the palps extremely 

 efficient tactile organs. In addition to the setae a number of pores are 

 present on the palps, of about the same size as the follicles of the setae. 

 These have presumably a sensory function and occur as follows: 



Segment 1 ; a single pore at the base, in the median line of the ventral 

 surface, also a cluster of six pores of varying size near the inner margin : 

 segment 2 ; one large pore somewhat beyond the middle of the segment 

 and one very small one at its base, both on the ventral surface: seg- 

 ment 3; two pores placed side by side on the ventral surface near the 

 middle of the segment : segment 4 ; one pore on the outer margin of the 

 segment near its base. 



The galeae are two-jointed, the first segment being slightly longer 

 than the second. Its outer margin is almost straight, while the inner 

 margin is bowed outwards, almost elbowed. It is without setae and 

 sensory pits. The second segment is rounded at the margin on either 

 side, but the outer is longer than the inner side and the galea inclined 

 inwards by reason of the manner of the articulation of the first with the 

 second segment. A large sensorium is borne near the middle of the 

 segment on the ventral surface, while four or five smaller ones are borne 

 on the outer margin between the middle and the base. The apex of the 

 segment is surrounded by a whorl of six short thick setae and within the 

 whorl a colourless thimble-shaped process is enclosed. This process is 

 incUned inwards and is barely one quarter the length of the preceding 

 segment. It is covered with rounded, colourless scales. 



The lacinia lies somewhat dorsal to the galea and is partially over- 

 lapped by it. It is flattened, composed of a single segment with the apex 

 bluntly pointed, almost triangular and reaching a little beyond the 

 first segment of the galea. On its outer margin it articulates behind 

 {i.e. dorsally to) the base of the galea, while its inner margin is continued 

 posteriorly to a level with the opening of the mouth, at the base of the 

 terminal lobe of the labium. The whole inner margin and apex is almost 

 concealed by a dense mass of wavy yellow hairs, which arise for the most 

 part near the outer margin of the organ and protrude into the space 

 before the mouth. At the base, near the angle of the inner margin two 



