190 Mr. H. Scott on 



lengths, on the whole stronger and more numerous at the 

 sides of the body and along the sutures between the seg- 

 ments. They are very easily detached and lost in preserved 

 material, and tig. 5 (PL X.) is taken from the only one of my 

 specimens in which they are at all complete: this figure 

 shows their arrangement. They are present, long and strong, 

 along the sutures dividing head from thorax, on the sides 

 of the prothorax, and the sutures dividing pro- from meso- 

 thorax ; the mesothorax has a group of short fine ones on 

 either side of the middle longitudinal line, but is otherwise 

 bare, even at the sides ; the small metathorax and first 

 abdominal segment have short fine setse on their margins 

 and also very scantily on their surfaces; on the rest of the 

 dorsal surface there is a fairly dense series along each suture, 

 composed of long setse on the front margin of each segment 

 and short ones on the hind margin of the preceding segment ; 

 the setae of these marginal series are shorter in the median 

 portion and longer at the sides ; the surfaces of the segments 

 Ijear scattered shorter setae in the median part and scattered 

 longer ones at the sides, there being a more or less bare 

 space between the median and lateral bristles, except on the 

 last two or three segments, where the median bristles are 

 longer and denser and practically continuous with the lateral 

 ones. 



Adhesive Pads. — In the material before me the pupa 

 adheres to the rock by means of eight adhesive pads, four 

 on either side of the ventral surface, on the third, fourth, 

 fifth, and sixth abdominal segments. The pupae examined 

 by Miiller had in most cases only three adhesive pads on 

 either side, on the fourth, fifth, and sixth segments (op. cit. 

 p. 77, pi. vii. fig. 3), and this is the number given by Kellogg 

 (1903, p. 213). 



Respiratory Horns (PI. IX. figs. 6-8). — Judging from 

 figures of pupae of various genera, the form of these organs 

 may be of some systematic value. As is well known, each 

 consists of four leaves or lamina, the two outer of which are 

 stronger, the two inner more delicate. Fig. 8 shows the 

 ground-plan of the four laminae of the left side of the body 

 in the material before me : m.l. is the median line of the 

 thorax ; it is seen that the anterior outer lamina (a.o.l.) is 

 convex on its anterior and concave on its posterior surface ; 

 the converse is the case with the posterior outer lamina 

 {p.o.l.) ; of the two inner laminae the posterior (p.i.l.) arises 

 slightly nearer the middle line than the anterior (a.i.l.) ; 

 the spiracle (.?.) is situated between these, a slit-like orifice 

 almost at right angles to the long axis of the bodv. The 



