226 Mr. IT. Scott on 



a median line of pale coniiexivum ; each part is whitish and 

 soft in its basal qnarter, brownish and more strongly 

 chitinized. in its remaining portions ; each bears short, 

 scattered, snberect bristles in its basal half, in the apical 

 half the bristles are absent towards the outer margin, but 

 scantily present near the median dividing-line ; immediately 

 on either side of the dividing-line the segment is produced into 

 an angular process, moi'c darkly pigmented, and having its 

 margin set with rather longer, stoutish, bristles. Behind 

 this basal tergite is an area of pale connexivum, bearing two 

 slightly darker areas, one on either side, about halfway 

 between the middle line and the side of the body ; each of 

 these areas bears several very short bristles at its anterior, 

 and several rather long bristles at its posterior, extremity ; 

 there is also a pair of bristles on the connexivum between 

 the jiosterior extremities of the dark areas. Anal segment 

 verv short, with a transverse series of long bristles at about 

 half its length ; this series is widely interrupted in the 

 middle, there being about four bristles on either side. 



Ventrally (PI. XII. fig. 17) the basal sternite is of great 

 length, with a dark median longitiidiual line^ and the short 

 bristles on its surface do not extend quite to tlie hind 

 margin ; the ctenidium does not extend right across the 

 margin, but ends on either side a little way from the angle, 

 the space between it and the angle bearing several marginal 

 bristles. The succeeding sternites (2, 3, and 4) are curiously 

 arched and bent forwards in the middle ; the chitinous 

 portions of sternites 2 and 3 are widely interrupted in the 

 middle, so that these sternites are represented by connexi- 

 vum medially and a chitinous plate on either side ; in 

 sternite 4 the chitinous portion is continuous, and. forms a 

 narrow arched strip (see PI. XII. fig. 17). The surfaces of 

 these stei'nites are bare, but their hind margins bear mode- 

 rately long bristles set at regular intervals, which, however, 

 are reduced in sternite 4 to only three or four bristles on 

 either side ; [it is only in specimens with abdomens greatly 

 distended that the median parts of these sternites are 

 visible ; in most they are hidden under the basal sternite]. 

 Sternite 5 is of peculiar shape ; produced in front into an 

 apex extending into the arch formed by the fourth sternite; 

 liind margin broadly rounded, without marginal bristles ; 

 the sternite is divided by a pale median longitudinal line ; it 

 has a pair of very short bristles, one on either side of the 

 median dividing-line near its base, a second pair of slightly 

 longer bristles similarly situated at about its middle, and 

 two or three still longer bristles on either side of the median 



