NOTES ON VARIOUS SPECIES OF TICKS FOUND IN THE 
UNITED STATES. 
r 
The role that Margaropus annulatus Say was found by Smith and 
Kilborne to play in the transmission of splenetic or Texas fever in 
cattle impressed upon investigators the importance of ticks as carriers 
of disease. Since that time the study of these creatures has progressed 
rapidly. Smith and Kilborne, Lounsbury, Theiler, Marchaux, Salim- 
beni, Dutton and Todd, Motas, Kossel, Ricketts, eal King are among 
oe who have sain aoe that ticks are the agents through Deh 
various diseases of man and other animals are transmitted. What 
is 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).4 
Seupuin ‘Absentee ss ote Oye aha, de Ee res ie Mk ee a Family ARGASID#. 
SS CUCU OLESEN Fess tte artis ne eee op ee ere ae ees we Family [xoprpz. 
Family ARGASID.- 
Capitulum at least its length from the anterior margin.........-. Genus Argas (p. 42). 
Capitulum under a beak-like projection, close to anterior margin. 
Genus Ornithodoros (p. 45). 
Family TIXODID. 
1. Palpi short, not or only slightly longer than broad; capitulum short. 
Subfamily RurpicePpHALIN#®, 2 
Palpi plainly longer than broad; capitulum longer ......-- Subfamily Ixopin~#, 5 
Subfamily RurprcePHALIn ©. 
2. Dorsal surface of capitulum hexagonal, the sides projecting in angles; male with 
analiplates. <7. Y72223_ 2 2 ee ea oe 0 le ae 3 
a This ae is based upon those of Salon onal Stiles (1901) ea ‘Banks (1904). “The 
genus Ceratixodes is not included (see p. 54). 
40 
