338 



habits, etc. The following persons have aided very materially 

 in collertinj^ specimens: Mr. C. A. Hart, systematic entomol- 

 ogist of the State Laboratory of Natnral History; Mr. J. J. Davis, 

 assistant to the State Entomologist; Mr. J. L. Fricer, A. M., 

 graduate stndent in entomology; and Messrs. J. Zetek. K. D. 

 Glasgow, and H. Glasgow, all students of the I'niversity of 

 Hlinois. 



Dr. S. A. Forbes has kindly permitted the author to work 

 up the oribatid collections of the State Lal)oratory of Natural 

 History, in which type specimens of the species described in 

 this paper have been deposited. 



Methods. 



hi making collections of oribatids several methods may l)e 

 employed. It is very desirable that these mites be collected 

 alive, in order that they may lie studied before being placed in 

 a preserving fluid. All notes on color and the position of the 

 bristles and pseudostigmatic organs should be made from living 

 specimens. Individual mites can be very readily transferred 

 on a camel's hair brush to a collecting vial, to be taken to the 

 laboratory and killed. 



Specimens are best killed in hot water or hot alcohol, when 

 they die in an extended position, most favorable for study. 

 While the specimens are still in the alcohol, notes should l)e 

 made on the shape of the pteromorphu', the psendostigmata, 

 and the pseudostigmatic organs, since it is hard to study the 

 form of these parts in the dorsal or ventral view^ of perma- 

 nently mounted specimens. Mr. Michael suggests the use 

 of dilute acetic acid instead of iilcohol as a preservative. 



In order to collect oribatids in large numbers, I use with 

 great success a modihcation of the Berlese method described 

 by Howard in '■Entomological News". Vol. XV 11.. 11)0(5, pages 

 49-54. If vegetable dei)ris is passed through a sieve before 

 being treated by the Herlese method, the numlier and variety 

 of small arthropods that may thus be obtained is surprisingly 

 large. A sinii)le but satisfactory method consists in placing 



