THE TROPICAL HORSE TICK. 199 
LIFE HISTORY. 
Observations on the biology of this species have been published 
by Hooker (1908) and by Newstead (1909). 
The egg (Table XCVI).—The first 3 ticks the oviposition of which 
was recorded were collected from the ears of a horse; the next 7 were 
Fic. 17.—The tropical horse tick, Dermacentor nitens: Distribution in North America and West Indies. 
The large dots show localities where the species has been collected in our investigation. The small dots 
indicate the probable range of the species in North America and the West Indies. 
picked from the ear of a mule; and the last 2 dropped from the ear 
of a bovine. 
The preoviposition period in the 12 ticks recorded varied from 3 to 
15 days. The minimum period occurred in the case of 2 females 
