(de. a. c. oudemans). notes on acari. 115 



hairy cusps are visible. Tarsus of palp dorsally and distally with 

 2 long tactile hairs, ventrally with 3 long tactile hairs and an inner 

 knife-shaped hair. 



Habitat most probally in humus, or in decaying leaves, for the 

 deutonymphae were attached to an Oiilscus asellus. 



Patria: Netherlands (Leiden). 



Found by Prof. Dr. J. Ritzema Bos, of Amsterdam. 



Type in collection Oudemans. 



15. Caligonus humilis (C. L Koch). 



(With Plate 12, fig. 23—33). 



1838. Rtigmaeus humilis Koch, Deu. Cr, Myr. Ar. 17.3. 



1842. Koch, Ueb. Ar. Syst. v. 3, p. 54. 



1885. Caligonus humilis Beri. Ac. Myr. Scorp. Ital. 22.5. 



1886. Beri. Ac. Myr. Scorp. Ital. 30.5 fig. 1, 5, 10. 



1890. R. Can. in G. Can. Prosp. Acarof. Ital. v. 4, p. 464. 



1903, Nov. 1. Achetés mirabilis Oudms. in Ent. Bericht, p. 101. 



I have found many specimens, but always dead, being drowned 

 in the ring of glycerine around the covering glass of unmounted 

 microscopical preparations. According to the length and slenderness 

 of the legs we may admit that these animals run as quickly as 

 Anystis baccarum (L.). 



If you will draw your attention for a moment to my figures 27 

 and 30 which show the rostrum seen from above and from below, 

 you may imagine how I at first was deceived and interpreted the 

 mandibles wrongly, viz. they being stylet-shaped and internal. The 

 consequence of this having wrongly interpreted the mandibles was 

 that I took the creatures as belonging to the Cheletinae, to a new 

 genus, which I called Achetés, and to a new species named Achetés 

 mirabilis. 



Accidentally I got under my eyes Berlese's representations 

 of the $ Caligonus humilis and I was struck by the close resem- 

 blance of his drawings of the rostrum seen from above and from 

 below, and of the palps. Finally I was convinced of the fact that 

 my Achetés mirabilis is nothing but Caligonus humilis of C. L 



