28 Arachnida and Myriopoda 



Plane Tree or gathering up the branches which have been lopped 

 off and children playing with the latter are said to complain of 

 itching places on the arms and neck, apparently caused by the 

 mite. It is possible that Artault is mistaken in thinking that this 

 trouble is due to the mite, for the species of Tetranychus normally 

 only attack vegetation. 



Family— BDELLIDA E. 

 Genus — Tji<lei<s, Koch. 



The mites of the genus Tydeus are small soft-bodied forms, 

 and are predatory in habit. 



Tydeus molestus, Moniez (Fig. 11), was reported as occurring 



during many years in 

 the gardens of a large 

 farm in Belgium, not 

 far from Ath. It is 

 alleged that this mite 

 was imported in guano 

 from Peru. At first it 

 was met with only in 

 FlG - 1:L - one spot, but after- 



Tydeus molestus Moniez. war a s increased greatly 



(After Moniez.) . -, • 



in numbers and in- 

 vaded the entire garden 

 of the farm. Human beings were attacked by this species, its 

 bites causing insupportable itching, and it was also found on dogs, 

 cats, poultry, etc. 



Sub-Obder— MESOSTIGMATA. 

 Family— PABASITIDAE (Gamasidae). 



The mites of the family Parasitidae (Gamasidae) are closely 

 allied to the ticks, but are usually very much smaller in size. Their 

 body is furnished with tough chitinous plates. The majority of 

 these Acari are free-living forms, but some of them are true 

 parasites. A" large number of species are found on rodents and in 

 their nests, others on birds, and a few on reptiles. 



The mandibles of the predatory species are in the form of 



