424 Mr. R. M'Lachlan on 



transverse nervules appear whitish in certain lights, as also 

 does the base of the furcation of the upper cubitus. 



Abdomen sliort, with fine silkj wiiitish pubescence ; all 

 the segments to the fifth transverse. Third dorsal segment 

 slightly produced into a rounded flap in its middle, appa- 

 rently covering a cavity iu the anterior portion of the fourth ; 

 sixth segment as long as the fourth and fiftii united, oblong, 

 the middle of its posterior end above is produced into two 

 shorty stronrj, cylindrical, obtuse, slightly divergent horns j 

 seventh longer than the sixth, obconical, curved upwards, 

 excised and narrowed at its base above ; eighth about the 

 length of the seventh, narrowly obconical, straight; cheli- 

 ferous segment short, the lateral pieces strongly rounded, the 

 chelae shorter than the segment, turned inwards and crossing ; 

 on tlie inner edge of each is a tooth about the middle, after 

 which the apical portion is excised, and there are pi-obably 

 one or two inner teeth at the extreme base ; appendages 

 flattened, closely applied to the edges of the rounded side- 

 lobes, gradually dilated to near the apical portion, which is 

 oblique inwardly, the inner edge with a fringe of rather 

 strong distant black hairs (the whole cheliferous segment is 

 more dusky in colour than those preceding it, and on its inner, 

 or upper side if extended, is an appearance as of two long 

 yellow hairy processes, damaged in the individual before me). 



Expanse, ^ 30 millim. 



Only one individual is before me, remarkable for its pale 

 colours and the conformation of the margin of the sixth 

 segment. 



Fam. AscalaphidsB. 

 Idricerus exilis, sp. n. 



Body slaty cinereous. Head above ver}' densely clothed 

 with long black hairs directed forward in a tuft between the 

 antennae ; on the front is a dense tuft of blackish hairs, 

 directed upwards, below the antennaj ; below this the hairs 

 are cinereous, mixed with black at the sides ; clypeus and 

 labrum yellow ; ])alpi testaceous ; mandibles piceous at tip. 

 Antennae wholly black (including the capitate club). Thorax 

 above with cinereous hairs, mixed with blackish on the sides ; 

 pleurae and breast with dense long whitish silky hairs. Legs 

 reddish ; tarsi black ; on the anterior tibitv beneath is (male 

 only?) a dense cushion of pale ochreous hairs occupying the 

 whole length ; si)urs black, those on the posterior tibiie about 

 as long as the first two tarsal joints ; chaws strong, black, 

 rather longer than the terminal tarsal joint. Abdomen with 



