221 



distinguishes the sexes, and cautiously exppresses hiraself about 

 the copulation tube »qui donne peut-Ure passage aux oeufs." He 

 saw the hairy hairs. He also remarked the ableness of the mites 

 to move their hairs. This is one of the reasons why the sarae 

 species of Glycypkagus is delineated so differently by various authors. 



1804. Latreille's Acarus domesticus is the same species; he 

 copies de Geer's fignre. 



1838 Hering's Sarcoptes hippopodos is nothing but the same 

 species. The oval body, wider posteriorly, the 9 copulation-tube, 

 the hairs, shorter than the body, are the known characteristics. 

 What seems strange: »allenthalben mit ganz kurzen Haaren (sam- 

 metartig) bedeckt", nevertheless really happens sometimes, viz. 

 when the auimal is treated with acetic acid or caustic kali ; then 

 it seems that the matrix is pressed through the numerous pores. 

 Further Hering mentions the movableness of the hairs, which are 

 hairy. That these creatures were found on a hoof of a horse, which 

 was visited by foot-itch, is not strange. Both Glycypkagus domes- 

 ticus and cadaverum were found by Mr. P. Koorevaar, of Ara- 

 sterdam, on such a hoof; both were abundant in the bean-straw 

 of the stable; I possess the preparations. 



1841. Nobody will hesitate to recognize Glycypkagus domesticus 

 (de Geer) in the drawing of Glycypkagus cursor of Gervais. 



1841. Koch's Acarus siro is our present species. He cites de 

 Geer's domesticus, which is right; he too cites Acarus putrescentiae 

 of Schrank, which is wrong. As to me this is the oldest name 

 of Tyroglypkus longior Gervais. 



[1841. Koch's Acarus dimidiatus is decidedly — Acarus putres- 

 centiae Schrank = Tyroglypkus longior Gerv.] 



1845. Guérin's Glycipkagus fecularum isa (ƒ domesticus, pressed be- 

 tween the glasses and badly drawn. It is found in putrifying potatoes. 



1852. One of the two of Hessling's drawings of Coelognatkus 

 morsitans is a Glycypkagus, most probably domesticus. It was found 

 in the hair of a man, infested by plica polonica (cirragra, Weichsel- 

 zopf, Judenzopf). The other is a Tyroglypkus, most probably 

 Aleurobius farinae (L.). 



