134 (dr. a. c. oudemans) list of dftch acari. 



Poppe, and compares them with the same organs in Picobia 

 hlpectinataj they exist in Cheyleius venustissinms and Cheyletus 

 erufUüis too; most probably they do exist in all ^^^Qcies, oî Cheyletus. 

 The two thick hairs, curved on their blunt distal end are 

 most probably used by the animal to clean the two comb-like 

 organs. 



Fig. 11. Anal opening and chitinous apparatus. The chitinous 

 skeleton of the anal opening is better understand by our fig. 11 

 than by any description. It is a pentagon whithin which a smaller 

 pentagon and a triangle are observed both constructed by chitinous 

 frames. Near tlie foremost frames there are two pairs of little 

 hairs, not quite symmetrical in their position (but this most probably 

 is an anomaly in my specimen); near the hindmost margin there 

 is a pair of little hairs and a pair of little fan-shaped scales; and 

 a little more to the centre, within the inner pentagon we observe 

 again a pair of little hairs. Quite before the large pentagon we 

 find two pairs of these hairs, and still a little further on, again 

 a pair of little hairs. These three pairs of little hairs are already 

 mentioned above, when speaking of the ventral surface of the 

 animal. From the top of the pentagon to the base of the triangle 

 runs the anal split. 



The animal , being a nympha , no genital apparatus is observable. 



Fig. 12. And now I come to the most remarkable observation 

 which I have made on my Cheyletus squamosus, viz. to the presense 

 of eyes. Between the second and third pair of scales on the margin 

 of the prosoma, near the so-called shoulders of the animal, there 

 is a lens-formed thickening of the chitinous integument, which I 

 have not been able to observe when the animal was not yet ma- 

 cerated in caustic kali. Unquestionably we have here to do with 

 eyes! They are perfectly margiftal. Fig. 12 is a figure of this eye 

 made under higher engrossing powers. It shows the eye between 

 two protuberances of the skin in which are planted the second 

 and third right marginal scales. 



Fig. 13 and 14. When I had found this eye I examined all 

 the figures of Cheyleti which I could compare, but no one shows 



