412 On two new Species 0/ Thelyphonidea. 



directed forwards on its underside ; the fourth joint is a little 

 longer than the third and straighter, and appeared to be some- 

 what serrated beneath ; the fifth or digital joint is a little 

 curved, slightly tapering, and has a sharp terminal claw, which 

 appeared to be movable ; beneath the fifth joint are some small 

 teeth. 



The abdomen has eight transverse corneous plates above, and 

 seven beneath ; the first of those beneath is much the largest, 

 and probably conceals the sexual parts, which, however, pre- 

 sented no external aperture beyond a line-like fissure : near the 

 fore margin of each of the three succeeding plates are two 

 small reddish-brown transverse slits, probably the openings to 

 the breathing-apparatus ; these openings form two parallel 

 longitudinal rows. In this view the spiracular openings would 

 be six in number ; but it was difficult to determine whether or 

 not there were two others connected with the hinder margin of 

 the first segment. Several very narrow plates, decreasing 

 rapidly in size, form a sort of postabdominal continuation, 

 terminating with a caudal appendage of a peculiar form, some- 

 what resembling the fluke of an anchor blunted at the point 

 and rounded at the hinder corners ; from this appendage there 

 issue a few long, straight, slender, diaphanous, spine-like 

 bristles, of which there are also numerous others beneath the 

 hinder part of the abdomen. 



Several examples of this species were received from Ceylon 

 (where they were found, under decayed leaves and rubbish, by 

 M. Ferdinandus in the E,oyal Botanic Gardens), and kindly 

 sent to me by Mr. G. H. K. Thwaites, together with numerous 

 rare and new spiders. 



I could not determine with any certainty whether or not 

 these examples were adult, or, indeed, of which sex they were ; 

 there was no apparent difference whatever of form or structural 

 detail by which the sex might be concluded. 



Nyctalops tenuicaudata, sp. n. PI. XXII. fig. 2. 



Length 2^ lines. 



In general form, structure, and colour this species resembles 

 the foregoing ; but it may readily be distinguished by the 

 almost total absence of the teeth at the extremity of the first 

 joint of the palpus, these being quite rudimentary ; those on 

 the other joints also appeared to be wanting ; another strong 

 character is also furnished by the caudal appendage being 

 slender and cylindrical. Possibly this may be the female of 

 the former species ; I am, however, inclined to think that it is 

 distinct. 



