Bd. V: II) 



THE ACARI. 



21 



gerlacJiei: the dorsal edge of the lower jaw is not raised and is without teeth. The 

 dorsal margin of the upper jaw has a sharp excavation at a level with ' 3 of the 

 length of the lower jaw. The upper jaw -is very broad for the two proximal thirds 

 of its length with a high, raised ventral edge, forming an angle of nearly 60' with 

 the dorsal edge of the lower jaw, when closed, from thence abruptly narrowing to- 

 wards the distal third, which is of nearly even length throughout. The posterior 

 dorsal hair is situated at a level with the middle of the lower jaw. 



The maxillary palps 

 (PL II, fig. II); the forth 

 joint shorter than the se- 

 cond one and comparatively 

 broader than in R. gigas, 

 being only very little more 

 than twice as long as broad. 



Rostrum (Te.xt-fig. 40) ; 

 the maxilla; are almost 

 wholly fused together, con- 

 stituting the short conical 

 rostrum, provided at the 

 tip vith a median short 

 lanceolate appendage; the 

 antero-lateral edges pro- 

 jecting into a semi-circular, 

 thin plate the edge of which is provided with 3 — 4 larger teeth and behind these 

 with several small ones. Two pairs of hairy bristles on the ventral side near the 

 base and two bare, more pointed hairs (Text-fig. 40). 



The Legs. The tarsi, especially those of the first pair of legs, provided at the 

 tip with numerous short, straight and blunt bristles (Text-fig. 46). The pulvilli 

 thick at the base, narrowing towards the end, slightly longer than the claws 

 (Text-fig. 47). 



Rhagidia megalocliela dift'ers widely from all species as yet known of the genus 

 by the enormous development and shape of the chela mandibuli. (Compare Text- 

 figs 35—39-) 



Locality: No. 14. one specimen. 



Fig. 35- Mandibles of R. gigas (from Natal). Fig. 36. R. gigas (from 



Egypt)- Fig. 37. R. marochela (from Falkland). Fig. 38. R. racovitzai 



(from Gerlache strait). Fig. 39. R. gelida (from Greenland). 



All figures 232 x . 



Notes on R. gigas subsp. Gerlachei Tkt., R. gigas R. Can. and R. 



gelida Thor. 



In order to ascertain whether TkOUESSART is justified in his treating R. gerlachei 

 as a subspecies of R. gigas, I submitted to an examination the specimens of the latter 



