NOTES ON VARIOUS SPECIES OF TICKS FOUND IX THE 
UNITED STATES. 
The r61e that Margaropus annulMus Say was found by Smith and 
Balborne to play m the transmission of splenetic or Texas fever in 
catt le impressed upon invesl igators the importance of ticks as carriers 
of disease. Since t hat time the study of these creatures has progressed 
rapidly. Smith and Kilborne, Lounsbury, Theiler, Maichaux. Salim- 
IxMii. Dution and Todd, Motas, Kossel, Ricketts, and King are among 
those who have demonstrated that ticks are the agents through which 
various diseases of man and other animals are transmitted. What 
i- greatly needed in this country at the present time is a convenient 
means of identifying the various species. This the writers have 
attempted, in a measure, to supply in the following pages, in which 
will also be found notes on the life history and habits of such species 
as they have encountered. 
CLASSIFICATION AND HABITS OF TICKS. 
The following key will enable one to determine the genera of the 
various ticks found in this country: 
KEY TO FAMILIES, SUBFAMILIES. AND NORTH AMERICAN 
GENERA OF TICKS. IXODOIDEA ." 
Scutum absenl Family Ai:<.a.-H'.k. 
Scutum presenl Family I kodid e. 
Family A K( IASI I ).]•;. 
Capitulum at leasl its length from the anterior margin Genus Argas p. 42). 
< Japitulum under a beak-like projecl ion, close to anterior margin. 
< nam- Ornithodoros p. 45 i. 
Family IXODID.F. 
1. Palpi short, nol or only slightly longer than broad; capitulum short. 
Subfamily Rhepk ephai i\ v. '2 
Palpi plainly longer than broad; capitulum longer Subfamily [xodinjb, 5 
Subfamily Rhipicephalin e. 
2. Dorsal surface of capitulum hexagonal, the sides projecting in angles; male with 
anal plates 3 
This table is based upon those of Salmon and Stiles (1901) and Banks L904 . The 
genus ( «T;ii ixodes is uol included (see p. 54 . 
40 
