SPECIES OF 



ARACHNIDA AND MYRIOPODA 



(SCOKPIONS, SPIDERS, MITES, 

 TICKS AND CENTIPEDES) 



INJURIOUS TO MAN 



By STANLEY HIEST 



Assistant in the Department of Zoology, British Museum 

 (Natural History). 



Class— ARACHNIDA. 



The class Arachnida is one of the principal divisions of the 

 Phylum Arthropoda,* and includes the Scorpions, Spiders, False 

 Scorpions, Harvestrnen, Mites, etc. A typical member of the 

 group can be distinguished at a glance from an insect by the 

 presence of four pairs of legs instead of three pairs. 



Some of the Arachnida are of great economic importance, 

 especially the large mites, popularly called ticks, which convey 

 several diseases of man and domestic animals. Only the forms 

 noxious to man are dealt with in the present pamphlet, but it is 

 hoped to issue others at a later date on the Acarine parasites of 

 domestic animals. 



Order— Scorpiones. 



The little black scorpions of the genus Euscorpius are common 

 in Southern Europe ; their sting is not followed by any very serious 



* For the subdivisions of this group and for a general account of the 

 Arachnida and Myriopoda, see the "Guide to the Crustacea, Arachnida, 

 Onychophora and Myriopoda," published by the Museum (1910, price Is.). 



