Geographical Distribution and Hosts 507 



GEOGRAPHICAL DISTRIBUTION AND HOSTS 



OF THE GENUS. 



Of the species and varieties we recognize, 3 occur in Europe, 15 in 

 Africa, 32 in Asia, 4 in Australasia and 3 in America. H. bispinosa 

 has ahnost to a certainty been recently imported into East Africa and 

 possibly into New South Wales with Indian cattle ; H. leachi may well 

 have reached Australia (again New South Wales) from India. If 

 we regard these species as not indigenous to the continents mentioned, 

 the number of indigenous species would be as follows : Europe (3), 

 Africa (14), Asia (32), Australia (2), America (3). 



This is in marked contrast to what we observe in the genus Ixodes. 

 If we add some species described by Bishopp (1911, pp. 197 et seq.), 

 Nuttall (1913, pp. 131-136), and Lahille (1913, p. 2) to those listed in 

 Part II of this work, varieties being excluded, we find the species 

 of Ixodes which we recognize as valid to-day distributed as follows: 

 Europe (10), Africa (13), Asia (10), Australia (10), America (25). It is 

 clear therefore that Asia is richest in species of Haemaphy salts and that 

 America possesses the greatest number of Ixodes. 



There are three species of Haemaphysalis which show a particularly 

 wide distribution : (1) H. cinnabarina occurs in North and South 

 America ; its var. punctata is found in Europe, Northern Africa, Asia 

 Minor and Transcaucasia ; (2) H. bispinosa occurs in Asia [British 

 East Africa and New South Wales]; (3) H. leachi occurs practically 

 throughout Africa, in different parts of Asia [and in New South 

 Wales]. The continents where these species are perhaps not indi- 

 genous are enclosed in [ ] brackets. 



Regarded from the point of view of the hosts which they infest, we 

 find but one species of Haemaphysalis which, as far as our knowledge 

 goes, would appear to be restricted to birds, i.e. H. hoodi. 



This is again in marked contrast to what we have observed in Ixodes 

 where certain species have been repeatedly found only on birds 

 (/. hrunneus, I. caledonicus, I. neuvianni,I. pidasj. signatus, I .unicavatus), 

 on Ornithorhynchus {I. ornithorhynchi) and bats (/. vespertilionis). In 

 this sense, the genus Ixodes appears more specialized than Haema- 

 physalis. 



In the list which follows, the scientific names of the hosts are given 

 as far as possible from the data at hand. 



