(dr. a. C. OUDEMANs). notes on ACAßl. 121 



1781. Then follows the Acarus eruditus of Schrank, whose 

 description and figure are bad. He considers the palps as legs, and yet 

 he describes and figures 8 legs in stead op 10 (including the palps). 

 So we should have reason to admit that Schrank has only observed 

 larvae, if he did not assert, that he saw larvae conning out of the 

 eggs, which were laid by the mother, under his eyes! Further 

 he asserts that these larvae rtsembled the mother, «etiam pedum 

 numero » (sic !). Schrank especially draws our attention on the 

 two long setae at the distal end of tarsi and on two lateral hairs 

 standing perpendicularly to t]>e animal's axis, and situated between 

 legs 2 and 3. 



1796. Latreille is the first who proposed a genus for this 

 species. He spells the name Cheyletas. Orlhographically we must 

 write Cheletes. He most probably did not observe the creature 

 himself, else he would have given a better description, though he 

 has well interpreted the palps, and has placed his Cheletes among 

 the Acari with 8 legs. Type Acarus eruditus Schrank. 



1826. Vqn Heyden quoting the genus Cheyletns Latr. says 

 only: ^lï^^^ Cheyletas eapulatus nob. (= ? Cheyl. eruditus La\r.)" 

 He is right in doing this query. It is possible that his species was 

 the same as Schrank's. 



1 836. In Heft 1 , n". 20, Koch describes and figures a Cheyletns 

 kirtmdinis, found in a nest of Apus apus L. The species may have 

 been the same as Schrank's. It is known that Cheleti often 

 frequent nests of birds and mammals. The beautiful colours depend 

 from food-particules in the intestinal track and from concrements 

 in the extretory organs. Most probably it is a ?. 



1836. His Cheyletns marginatus (Heft 1, n"^. 21) is found in 

 moss, is larger than the foregoing species. Yet is is possible that 

 it is the same, specimens of which vary in length and breadth 

 according to their being young or old (after having left the 

 nymphal skin), more or less fed, or more or less pregnant. Most 

 probably it is a ?. The difference in the possession of 6 posterior 

 hairs in stead of 4, and of a lateral smaller hair behind the long 

 one, are of little value. How often are we mistaken in the number 



