138 



Genus Ixodes 



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I Anal grooves short, strongly divergent (Europe, 

 on small mammals) 

 Anal grooves long, sub-parallel (Australia) . 



(Article 1 of palps enlarged, cup-like (Australia) . 



1 » ,. .. normal 



( Anal grooves short, divergent .... 

 I „ „ long, sub-parallel .... 



(Scutum sub-circular ; slight cornua 

 | „ elongate ; no cornua (on bats) 



(Sharp spurs on trochanters (Africa) 



(No trochantal spurs 



Coxae trenchant; scutum smooth, with fine punc- 

 tations (Africa) 



Coxal borders rounded ; scutum rugose, with 

 large punctations 



(Scutum slightly rugose ; widest rather in front of 

 middle (Europe) 

 Scutum very rugose ; widest in middle (America) 



No internal spur, but a blunt external spur on 

 coxa I ....... 



Coxa I with internal spur 



Spurs on trochanters (?on birds, Nightingale 

 Island) ........ 



No spurs on trochanters 



Porose areas large, confluent, occupying most of 



basis capituli (on marine birds) 

 Porose areas tranversely elongate, separate (on 



marine birds) 



Internal coxal spur long ..... 

 „ „ „ short; a slight external spur 



or tooth 



(A strong external spur ..... 

 (External spur short or absent .... 



(Both spurs long, parallel, sub-equal (India) 

 (Internal spur much the longer .... 



(Anal grooves short, anus very posterior (Mexico) . 

 1 » „ long (Brazil) 



