320 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
the intestine posteriorly. As soon as this median division passes the 
uterus in the female or the seminal vesicles in the male, it gives off 
downward a small tube that continually decreases in size and goes 
toward the cloaca. This is shown in the side view of the alimentary 
canal (pi. 19, fig. 7). The larger part of the median tube continues 
posteriorly. The further description of the three main branches of 
the intestine is similar. They each branch into parts—four each in 
the specimen figured—which end blindly. 
For convenience’ sake these different diverticula of the alimentary 
canal have been labeled 7, 2, and 3, beginning from the right side, 
and their subdivisions have been lettered a, b , c, and d. The ali¬ 
mentary canal as seen from above is shown, thus labeled, in fig. 8 
(pi. 19). The division is something like that shown in Pagen- 
stecher’s figs. 1 and 3, pi. 2, for Ixodes ricinus, but differs in the 
place of origin and the amount of branching of the lateral portions. 
Pagenstecher represents all the diverticula as radiating from a com¬ 
mon center while in Boophilus they arise from the three branches 
just described. 
In fig. 9 (pi. 19) the same alimentary canal is shown as seen from 
the right side. Diverticulum la is a short one. It turns back on 
itself and ends blindly, pointing downward; lb extends anteriorly 
outward and downward and crumples up at the limiting boundary, 
the hypodermis; lc extends directly outward and dowmward, bending 
forward and then backward, then forward again to end below the 
midplane of the body; Id extends backward as the main portion of 
division 7, after giving off caeca 7a, lb , and 7c, and reaches the pos¬ 
terior end of the animal. Here it bends sharply forward and follows 
the floor of the body cavity to the anterior end again, where it turns 
upward and ends blindly above the level of the end of 7c. This 
brings out the point indicated by the dotted lines in fig. 7 (pi. 19), 
that the principal diverticula, Id , 2a , 2b, 2c, 2d, and 3d, on account 
of their bending down at the posterior end and extending forward, 
are from one to one and a half times the length of the body. 
These caeca are packed away irregularly as fig. 10 (pi. 19) shows. 
This is a view of the same alimentary canal as seen from below. 
The comparative symmetry has disappeared. Neither 7a, 3a, nor 
3b was seen at all. The diverticula of the left branch of the canal 
seem to have extended farther back before turning forward; 3d is 
seen to be much farther back than Id. Conversely, however, it 
does not reach to the anterior end of the body cavity. 
