14 IXODOIDEA, OR TICKS, OF THE UNITED STATES, 



instead of subfamily and tribal names based on the genus. He, how- 

 ever, keeps Dermacentof in the same group as Rhipicephalus, which 

 I consider ill-advised and have placed them apart, Dei'macentor 

 closer to Arnljlyomiina. Mr. Warburton has also put more value on 

 the length of the palpi than I think justified, and also used, more 

 than I, the secondary sexual characters of the male. A summary 

 of my classification appeared in the Proceedings of the Entomo- 

 logical Society of Washington, Volume VIII, page 62, August, 190T. 



Doctor Neumann has also lately (Sjostedts Kili-mandjaro-Meru 

 Expedition, page 20) given an arrangement of the genera in three 

 sections. He, however, places, and I believe wrongly, Uyalo7nma 

 near Rhipicephalus. 



Our two families of ticks are very different, as seen from the fol- 

 lowing statement of characters : 



Table of the Families. 



No corneous shield on dorsnm ; head hidden beneath front of body ; anns near 

 middle of venter; skin ronghened Argasidw. 



A corneons shield present on dorsum ; head distinct in front of body ; anus 

 behind the middle of venter; skin only tinely striated Idodidw. 



Family ARGASIDiE. 



No dorsal shield; head hidden under front of body; anus near 

 middle of venter; skin roughened ; coxa> usually contiguous or nearly 

 so ; tarsi without apical pulvillum. 



In the larvae the head and mouth parts are distinct, in front of the 

 body, as in the true ticks; there are also indications of a pulvillum 

 at base of claws. However, there is not as much difference between 

 the sexes as in the Ixodidse; so it seems probable that each family has 

 specialized along different lines. The argasids remain on their hosts 

 for only a short time, and many of them are most active at night. 



Our tAvo genera are closely related, but may be distinguished as 

 follows : 



TA15LE OF THE GeNERA. 



Margin of body thin and acute Argus. 



Margin of body rounded =. Ornithodoros. 



Genus ARGAS Latreille. 



Body strongly depressed, elongate oval in shape, usually narrower 

 in front, margins thin and acute ; palpi hidden under front of body. 

 Skin strongly wrinkled and with scattered smooth patches, most nu- 

 merous near the margin. No eyes. 



Type. — A. reflex us Fabricius. 



The famous " Miana bug'' of Persia (Argtus per.sic>/s Fischer) 

 belongs to this genus. The bite of this species was reputed to pro- 



