I. percavatus var. rothschildi 221 



auricula forming a stout retrograde process. Digit? Hypostome 

 narrow, rounded distally, 4 1 4, teeth equal. Palps short, article 2 barely 

 longer than 3, article 1 triangular ventrally, with an anterior point 

 internally and a posterior point. Legs of medium length, dark red- 

 brown. Coxae I— III bear spurs at the postero-internal angle, the spurs 

 diminishing in size and absent on coxa IV ; coxa I bears an external 

 spur which is slightly longer than broad, short, pointed, almost trans- 

 verse ; a shorter spur at the postero-external angle of coxae II-IV. 

 A retrograde ventral spur on the distal border of trochanters 1-4 (see 

 Fig. 216). Tarsi of medium length tapering obliquely, those of pair 

 1 long and slender. 



Description based on four dried gorged ?s, slightly mutilated, from 

 Nightingale Island, of the Tristan d'Acunha group (W. of the Cape of 

 Good Hope ; Brit. Mus.). Species allied to Ixodes neumanni Nuttall 

 and Warburton. 



Ixodes percavatus var. rothschildi n. var. Nuttall 

 and Warburton. 



Male : unknown. 



Female : differs from the type in the following respects : Cornua 

 strong, and recurved dorsally ; porose areas smaller, the interval equal to 

 half their width ; no retrograde spur on trochanter 4. 



Nymph : resembling the ? in all respects, except sexual charac- 

 teristics. 



Described from (N. 634) 2 $s and 3 os, taken from a puffin (ex 

 Rothschild coll., no locality recorded). 



33. IXODES PILOSUS Koch, 1844. 



Figs. 217-221 (original). 



Lit. and Icon. : Koch, 1844, p. 233; 1847, p. 105, PI. XXI, Fig. 79 ( ? ) 

 Neumann, 1899, p. 151 ; 1901, p. 288. 

 Lounsbury, 1900a, p. 47; 1900c, p. 32; 1904, p. 29. 

 Mally, 1904, p. 7. 

 Howard, C. W., 1908, p. 94. 

 Donitz, 1910, p. 435, PI. XVI b, Fig. 6 (? : capitulum, ventral aspect; good). 



The " Paralysis Tick " or " Russet Tick " of Cape Colony. 



Male (Fig. 217): long-oval, 2'8 x 16 mm. Scutum oval, leaving a 

 narrow marginal fold ; cervical grooves shallow, parallel at first, then 



