Bd. V: II) 



THE ACARI. 



13 



pairs on the inner side of cox.x' III and one pair on the inner side of coxje IV 

 behind their middle. 



Near the anterior margin, behind the first pair of hairs, is to be seen a pair of 

 long, transversal, light-coloured grooves. This feature, in connection \\ith the super- 

 numerary number of sternal hairs, seems to indicate that the portion in front of 

 the grooves is homologuons to the second pair of jugular shields, which is to be 

 found in the other species of Hydrogamasus. Thus in the present species, if my 

 interpretation be correct, the posterior pair of jugular shields has coalesced with 

 the sternal shield. 



The sternal shield extends backward as far as the hind margin of coxa; IV, 

 gradually narrowing backwards; hind margin slightly convexe. The genital aperture 

 inserted in an incision of the front margin of the sternal shield. 



Ventri-anal shield large, covering nearly the whole belly, shaped like that of 

 H. salini/s Lab. Anal aperture situated close to the posterior margin. 



Legs. Legs I long and slender, with long coxœ bent like a knee; claws and 

 caruncles smaller than those of the other legs. Legs II (PI. II, fig. 6) thick, with 

 great calcar femoralis curved sharp!)- upwards, of uniform width throughout and 

 ending in a sharp, chiselshaped square edge; no processus axillaris, only a short hair 

 in its place; processus stridularis genitalis a rather \o\\ ridge with rounded edge; 

 processus tibialis perpendicular, short, thorn-shaped. The tarsus has a very remark- 

 able shape and bears a great resemblance to that of Gaviasellus Racovitzai: it is a 

 little in front of the joint between basi-and telotarsus, curved downwards and on the 



ej- s 4. 



Hvdrogamasits antarcticus Tgdh. 



Fig. 18. Palp, cf. 112 X. Fig. 19. Epistoma, cf- 464 x. Fig. 20. Ambulacre II. 464 x. Fig. 21. Am- 



bulacre I. 464 x. Fig. 22. Jugular-, genital- and anterior part of sternal shield, cf. 232 x. Fig. 23. Anterior 



part of hypostoma, cT- 464 x . Fig. 24. Basitarsus and part of telotarsus with processus tarsalis cT- 



Dorsal view 464 x . Fig. 25. The same d" side view. 464 x . 



