BY VERA A. IRXVIX-SMITH. 7^7 



had only a single row of head-set^e, and only three pairs of 

 ventral setcf (PI. xlvii., b). But it is possible that this was a 

 damaged specimen, since the sette in some of the others examined 

 broke oft* with handling. 



The setie of the inner rows (Fig. 2 7«) are much sliorter than 

 those of the outer rows (Fig. 276), which are often longer than 

 the width of the body in that region; and longer in the male 

 than in the female, averaging, in the former, 0*045 mm., and 

 0*040 mm. in the latter. The longest setto are at the anterior 

 end of the rows. Here, they are more closely crowded than 

 they are further back. All the compound seta? are similar in 

 character. Each consists of a proximal, elongated, holhjw rod, 

 and a small, expanded, movably-jointed end-segment, with a deep 

 indentation in its distal margin. The simple setit?, which alter- 

 nate with them in the male, are of equal length, but very slender 

 and delicate, and tapering to a fine point. The body-hairs are 

 a very consjDicuous feature in this species. Thev are verv 

 long, relatively to the width of the trunk; and all have a bulb- 

 Hke swelling at the base(Figs. 26, 27, 35, t.h.). They are arranged 

 in eight longitudinal rows, two lateral rows on each side, two 

 dorsal, and two ventral, which are all continued over the head 

 to the anterior end of the rostrum (PI. xlvi.). The dorsal and 

 dorso-lateral rows extend down to the margin of the tail, but 

 the ventral and ventro-lateral rows only to the beginning of the 

 ventral setae, with the inner and outer rows of which they are 

 respectively continuous. The number of hairs in each row is 

 limited, and appears to be fairly constant. On the trunk, there 

 are, in the dorsal rows, 20-30 long hairs; dorso-lateral rows, 19- 

 27; ventro-lateral, 15-17; and ventral, 15-23. On the head, 

 there are, on the hinder region, 3-5 hairs; on the banded area, 

 two; and, on the rostrum, 3-4, the terminal hair of each of the 

 eight rows being situated right at the anterioi- margin of the 

 cuticle, so that there are eight hairs forming a circle surrounding 

 the lip-like prominence, in the centre of which, the mouth is 

 situated (Fig. 25, a.h.). Immediately round the small mouth- 

 opening, there is another ring of small hairs, about six apparently, 



