122 (dr. a. 0. OUDEMANS). NOTES ON ACARI. 



and situation of hairs, when we contemplate such small creatures 

 under low magnifying powers. 



1839. His Cheyletus eriidUus (Heft 23, n"^. 20) found by him 

 in great quantities in dust of corn, of pulse, of hemp-seed, etc., 

 possibly is tlie same species as Schrank's, and certainly that of 

 which I present to my readers new drawings and description. 



4839. Cheyletus casalis Koch (Heft 23, n^. 21) is found accom- 

 panying Ch. eruditns, bot not often. Possibly it is Ch. erudiius 

 itself, and a S. 



1843. I have not been in the opportunity to consult Contarini's 

 works. 



1843. Guerin's ligure is a copy of that of Koch. 



1844. Du JARDIN is the first who describes the styliform man- 

 dibles and the pectiniform hairs on the palpal tarsus (Ann. Sc. 

 Nat.), and who discovered tracheae (Compi. Rend.) 



1852. Euiarsiis cancriformis is the name, given by a physician, 

 Hessling, to a creature found by him on the head of men, visited 

 by ijilica polonica [cirragra, Weichzelzopf, Wichlelzopf, Judenzopf), 

 together with other mites. We have possibly to do with Cheletes 

 eruditas. 



1860. VAN DER Hoeven ; not anything new to science. 



1866. Beck is the discoverer of parlhenogenetic reproduction of 

 «an Acarus», which positively is Cheletes ernditus. His drawing is the 

 best I ever saw (Compare his drawing with mine, fig. 44). He never 

 was able to detect a i, which is strange, as ^ are not so rare as 

 is usually believed. He has bred only one nympha, which is still 

 stranger, for there are two ! ! 



1867. FuMOUZE and Robin are the first wo give an ample des- 

 cription (and tolerably good figures) of a species of Cheletes, which 

 I consider different from Ch. eruditus Schrank. Yet they mention 

 a species with two hnohs at the inner side of the hase of the 

 claw of the palp, and with a spine only (not accompanyed by a 

 tactile hair) on the middle of the dorsal side of tarsus i, chardici er s 

 of that animal which I consider as Ch. eruditus Schrank. 



1869. Johnston's paper was inaccessible to me. 



