APACHYUS. 35 



adult female. The full number of dorsal segments is also visible 

 in both. 



We may therefore conclude that, as this lobed ventral segment 

 is far more acute and produced in the $ than in the d , it is more 

 pronounced in the last instar, and consequently shows the sex at 

 this stage better than any other part or organ. 



Variation. 



This species varies considerably in size. The following are the 

 dimensions of a number of specimens iu different collections from 

 various localities, measured from the mouth to the apex of the 

 anal process. 



Burma (Genoa Mns.) 42 mm. 40 mm. 



Tonkin (coll. Burr) 43 „ 41 „ 



" 31 „ 



Bhutan {Paris Mus.) 30 „ 



It is easy to recognize by its usually great size and the form of 

 the anal process and forceps. 



2. Apachyus pascoei, Kirhy* 



Apachyus pascoei, Eirby, (91) p. 521, pi. 20, fig. 1 ; (04j p. 3. 



Very closely resembles A.fecp,, Borm., the description of which 

 applies well to this species, with the following points of distinction. 

 The colour is generally decidedly darker, being a deep chocolate- 

 brown ; the forceps are less coarsely pitted ; the abdomen is 

 shorter and decidedly broader in proportion. The last dorsal 

 segment is rugose rather than granulose, and the granules are far 

 more densely crowded ; finally the anal process is more angular, 

 owing to the fact that the projections at the edges, not only in the 

 middle but at the sides, are more marked, and so emphasize the 

 angles. J . 



6 



Length of body. . , 35 min. 



„ forceps 8 „ 



Assam : Sylhet {Brit. Mus.). 



Type iu the British Museum. 



This species has always been sunk as a synonym of A. fece, 

 Borm., but a comparison of Kirby's type with authentic specimens 

 of A. fece from de Bormans' own collection shows the distinctions 

 as given above. It is consequently prudent to suspend judgment. 

 and leave the final decision to collectors on the spot. 



d2 



