The lAfe-history of an Acarus, &e. By A. D. Michael. 389 



Female. 



Colour yellowisli cbitinous brown, of medium tint ; the white 

 excretory organs show through the dorsal surface. 



Texture polished, particularly the anterior part of the cara- 

 pace, which is slightly transparent. 



General Form oval ; not quite so short and hroad as in 

 D. homhi when living, but becomes so after death. Form varies a 

 little according to the action of the muscles. 



The anterior portion is covered by a semi-lunar carapace resem- 

 bling that of Limidus ; this projects beyond the body anteriorly 

 and laterally, and extends about to the insertion of the third legs. 

 The three anterior pairs of legs are covered by the carapace when 

 the creature is at rest, but project further beyond it than in homhi 

 at other times. Body behind the third legs covered by a projecting 

 carapace divided mio four segments. 



Cephalothorax small, distinctly divided from the abdomen 

 (when seen from below). Kostrum short, broad, folded down on 

 the ventral surface, and similar to other species of the genus. 

 The ventral surface has a median straight sternum, with apodemata 

 running to the epimera of the legs as in B. homhi. At the edge 

 of the body between the first and second pairs of legs are tivo small 

 glohidar organs on short peduncles very similar to the pseudo- 

 stigma tic organs of the Orihatidse. 



Abdomen smaller than the carapace, but large in proportion 

 to the cephalothorax, approaching the circular form. There is a 

 large serrated hair at each antero-lateral angle of the carapace, one 

 pair of similar hairs on the hind part of the lateral, and two on 

 the hind margin, but all springing from the dorsal surface some 

 distance within the margin. There are also four pairs of unser- 

 rated curved spines on the actual margin. 



The Legs. The first leg has not got the enlarged and fused 

 tarsal and tihial joints, nor the great holding claw which are 

 found in D. homhi ; the absence of these characters forms the prin- 

 cipal distinction between the species. The first leg of this species 

 appears to be a tactile organ, the claw is quite rudimentary. The 

 fourth leg has what appears to be some indication of a caruncle. 

 In other respects the legs correspond fairly to those of homhi. 



Male. 



Colour semi-transparent white. 



Texture rough and leathery, not hard nor chitinous. 



General Form an oval, with the broad end foremost and 

 the small end produced so as to be rod-like, or it might be called 

 peg-top shaped, if so homely a comparison be admissible. 



Cephalothorax divided from the abdomen by a line, but 



