Generic Ch aracters 



351 



Generic Characters : Metastriata, i.e., with anal grooves embracing 

 the units posteriorly. Usually of small size. Scutum inornate and 

 without eyes, and in the female, tvithout lateral grooves. Capitulum 

 with base sub-rectangular, and with palps normally short and conical, 

 broadest near the posterior end of article 2, which (except in rare cases) 

 projects latei'ally beyond the base. Sexual dimorphism slight, the male 

 possessing no ventral plates or shields. Coxa I never bifid ; trochanter I 

 with a blade-like dorsal retrograde process. 



The chief difficulties presented by the genus Haemaphysalis arise 

 from the absence of characteristics — such as eyes, colour-markings, anal 

 armature in the </, etc. — which are of great specific value in other 

 genera. The prevailing colour is yellow, in ungorged specimens, and 

 the general integument is rather highly chitinised, so that those 

 structures which in most ticks are conspicuous by their comparative 



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Fig. 308. HaemcqyJiysalis wellingtoni i in dorsal and ventral aspects, ? in dorsal 

 aspect. (Reprinted from Part II, Fig. 120.) To show the generic characters and 

 nomenclature of parts. 



hardness stand out in less salient relief. Thus, the scutum of an unfed 

 nymph is sometimes only visible after rather close examination. The 

 capitulum is in most cases much alike in the ^ and $ so that in many 

 species identification is almost equally easy from either sex. There 

 are exceptional cases, however (e.g. H. concinna, H. cornigera, etc.), in 

 which the cT palps have striking peculiarities not found in those of 

 the $ . The sexes are more frequently dimorphic as regards the coxal 

 armature. Wherever the coxal spines are strongly developed in the 

 cf their peculiarities are only very faintly echoed in the $ . There is 



23—2 



