Marshall—A Parasitic Ostracod. 
123 
without the direction of the tendon being changed and also 
beeps it from, pressing on the two setae over which it passes. 
Opposing this last muscle is one, the only other muscle in the 
antenna., which, arising at the base of the third segment is in¬ 
serted above on the base of the claws; its insertion is also’ ten¬ 
dinous. 
Of the three setae on this appendage two> are nearly similar 
and are situated one at the distal end of the third, and the other 
near the middle of the fourth segment. Each of these consists 
of a large basal piece followed by numerous small segments; 
they resemble the setae of the first antenna in all respects ex¬ 
cept their greater thickness. 
Differing, however, from all other setae; is the one borne on 
the distal end of the 1 first segment, the flabellum or urticating 
seta. It is curved, hollow, tapering and long; its length being 
equal to that of the antenna minus the terminal claws. At its 
base it receives the secretion from the adhesive gland; this pass¬ 
ing through the seta exudes from the hollow end and is used to 
help give a firm support when the animal is; crawling on smooth 
surfaces where the claws would not take hold. When examin¬ 
ing living specimens under the microscope this use could eas¬ 
ily be seen. Wherever the flabellum was raised from the slide 
or cover glass a small drop of a nearly transparent viscid mat¬ 
ter could be seen marking the spot where the end of the flabel¬ 
lum had been, while often a fine thread would be distinguished 
connecting one drop with another. This secretion and its con¬ 
nection with the hollow flabellum has been, figured a number of 
times, although the name used by Zemkeir (19), S. Eischer (6) 
and others, poison-gland, does not signify its use. There can be 
no doubt but that the secretion is used to enable! the Ostracod to 
crawl on smjooth surfaces where the claws would be of no use, 
and such being the case, a more significant name would be ad¬ 
hesive gland. At the end of the antenna are the three curved 
claws each armed with a, number of stiff straight bristles. The 
middle claw is much smaller than the others. They all appear 
connected at their base with an irregular chitinous piece on 
which the tendons of both, muscles are inserted. By this ar¬ 
rangement the three claws move in unison, making it possible 
that two* muscles can move them all. 
