380 



difference is masked by the small degree of individual variation. The leg 

 bristles are more modest, less robust. 



From the above occurrence records it may be regarded as a 

 typically arboreal species, especially of the Juniperus-Andropo- 

 gon community. The larvae and nymphs are found chiefly on 

 the ground. Such minute species may readily have been intro- 

 duced from Europe on Dutch bulbs and nursery stock, the 

 larvae on the roots and mossy packing, the adults in crevices of 

 bark, or roots and packing. To what extent this has occurred, 

 in the early colonial days is a matter for conjecture. Whether 

 H. h. arborea has become differentiated since these early days or 

 from what earlier time, is likewise not at present known. How- 

 beit, it is conceivable that more recently introduced European 

 material (with straight pseudostigmatic organs) may be found 

 spotted here and there among the H. h. arborea, especially near 

 human habitations, in arboretums and botanical gardens. 



One specimen was noticed with fungus spores within its abdo- 

 men. As it is an arboreal species its connection with the death 

 of junipers (and other related genera) and with black knot of 

 cherry should be investigated. 



Acknowledgements. — Slides of which the number includes the 

 letter B, were kindly loaned me by Nathan Banks, and are de- 

 posited at the Museum of Comparative Zoology; slides bearing 

 the initial G were kindly furnished me by Philip Garman and 

 are deposited at the Connecticut Agricultural Experiment Sta- 

 tion; those bearing no capital letter are being deposited at the 

 Boston Society of Natural History. 



Literature. 

 Banks, Nathan. 



1895. On the Oribatoidea of the United States. Trans. Amer. Ent. Soc. 

 22: 1-16. 

 Berlese, Antonio. 



1882-1900. Acari, Myriapoda et Scorpiones hucusque in Italia reperta. 

 101 fascicles, 10 vol. Padova. 

 Hermann, Jean-Frederic. 



1804. Memoire Apterologique. 152 p., 9 pi. Strasbourg. 

 Koch, C. L. 



1835-44. Deutschlands Crustaceen, Myriapoden und Arachniden. Re- 

 gensberg. 



