WILLIAMS: BOOPHILUS’ ANNULATUS. 
323 
gland ducts. One of these gland ducts leads through the cuticula 
into an expanded chamber in the hypodermis, the walls of which 
may show from one to five nuclei. The chamber may extend inward 
from the cuticula more than twice the average thickness of the hypo¬ 
dermis—in one instance | of a millimeter. Fig. 16 (pi. 21) shows 
two glands and two bits of cuticula, one of which has a gland duct 
through it and the other a passage for a hair. These glands seem 
most abundant on the posterior part of the abdomen of the female. 
They are very variable in shape and in size. 
According to Lang ('94, p. 540), glands which do not open in con¬ 
nection with the legs have been considered oil glands, scent glands, 
poison glands, etc. As an example of the last sort he instances the 
paired poison glands at the end of the abdomen of the scorpion. 
Excretory System. 
The excretory system in Boophilus does not correspond to that in 
Ixodes ricinus. In that form as described by Pagenstecher (’61) 
the organ of excretion consists of two long unbranched tubes of 
small diameter opening into the cloaca and so entangled with the 
salivary glands and so coiled that they were to be isolated with diffi¬ 
culty. 
According to Kersey (’72) the urinary tubules of Ixodes dugesii 
are blind tubes, subclavate in the fore part of the body, and open 
into the last part of the intestine, where they form a sort of urinary 
bladder. 
In Boophilus the excretory system is constituted on the plan 
already outlined by the alimentary canal (compare fig. 8, pi. 19, and 
fig. 15, pi. 20). Three main divisions, one lying above the origin of 
the legs on each side and one in the midline, are connected by a 
cross tube just above and behind the similar cross connection of the 
alimentary canal. 
The main part of these tubes is on the dorsal side of the animal 
just beneath the hypodermis. Fig. 15 (pi. 20) shows the relations 
of these divisions. The lateral portions send out small twigs which 
fit in as best they may above the musculature of the legs and then 
continue backward, turning with the corresponding intestine diver- 
