OLASSIFICATION AND HABITS OF TICKS. 55 
were described as belonging to this genus, as is the case with the 
species of Say, Fitch, and Packard. 
Of the genera represented in the United States this has the largest 
number of species. Fourteen are’ recognized, as follows:¢ 
I. ricinus L., I. frontalis Panzer, I. scapularis Say, I. fuscus Say, 
I. brunneus Koch, I. urize White, [. cooket Packard (Synonyms: J. 
cruciarius Fitch, and J. heragonus of S. & S., on the authority of 
Nathan Banks), J. arcticus Osb., I. diversifossus Neum., [. dentatus 
Neum., 7. angustus Neum., J. inchoatus Neum., I. sculptus Neum., and 
I. californicus Banks. 
Of these, four have been taken in Texas by agents of this Bureau— 
ricinus, ek el, scapularis, and sculptus. 
Coamperatieels little is known of the life cycle of the species of 
Ixodes. The work of E. G. Wheler on ‘‘Louping Ill and the Grass 
Tick” U/. ricinus) is about all that has been done. It seems prob- 
able that all species drop to molt. 
As Mally ascertained to be the case with /. pilosus in South 
Africa, we have found engorged females of J. scapularis to dry up 
in captivity before ovipositing. From Wheler’s studies and our 
experience moisture seems to be a necessity in order that molting 
may take place. 
The longevity of the larve of ticks of this genus must be excep- 
tional, even when some of the long-lived species of other genera 
are considered. Wheler mentions larve (J. plumbeus?) which 
hatched on October 9, 1898, from eggs laid in August, that lived 
until the beginning of August, 1899, or about 10 months. They 
were kept in a bottle with a sprig of moss and some damp sand. 
AMERICAN CASTOR BEAN TICK. 
(Ixodes cookei Packard. ) 
Synonymy (on the authority of Nathan Banks): Lvodes cruciarius Fitch; I. hexagonus 
8. &S. (not hevagonus Leach, 1815); J. hexagonus var. longispinosa Neum. 
This species(PI. III, fig. 4) was described by Packard from speci- 
mens on a woodchuck, Arctomys monax, at Salem, Mass. Neu- 
mann, in 1899, placed the American form with the European J. 
hexagonus, but in 1901 he separated the two as varieties. Salmon 
and Stiles, in 1901, followed Neumann, who at that time had all their 
specimens. Banks has examined the National Museum material 
and considers longispinosa the same as I. cookei of Packard, but 
states that there may be a true hexagonus in this country; though he 
has not seen it. 
@ According to Nathan Banks, J. nigrolineatus Packard is a Dermacentor. 
