Bd. V: ii) 
THE ACARI. 
23 
Fig. 40. Rostrum of R. ?nacrochela , side view. 620 x. Fig. 41. Rostrum of R. gigas (from Natal), dorsal 
view. 416 x . Fig. 42. Rostrum of R. gelida dorsal view. 416 x. 
Fig. 43. R. gigas (from Egypt). Fig. 44. R. gelida (from Greenland). Fig. 45. R. Racovitzai (Gerlache 
strait). Figs 46 and 47. R. megalochela (from Observatory Island) 1st & 4th pair of legs. 
ventral tooth near the base; the claws of the ist pair of legs are heterodactylus , one 
claw being more slender and straight, curved only at the tip, while the other one is 
more stout and curved. 
R. gelida and R. megalochela (Text-figs. 44, 46 and 47); the ambulacres of the 
same shape; the pulvillum widens at the base, is more stout than in R. gigas and 
slightly longer than the claws. 
R. gerlachei (Text-fig. 45); the pulvillum shaped as in R. gelida and megalochela 
but longer, exceeding the claws by x / 3 of its length. 
