248 E. A. ANDREWS 
to cut the whole appendage away from the sternum. In this 
membrane there is an articular, whitish plate that is seen in figs. 
m1 andtv. The whole base is pyramidal and except the posterior 
all its faces (figs. 1, 111, Iv) are convex and rounded. 
The neck is the narrowest part, before the sudden enlargement 
of the spiral part; it is the smallest of the three regions; and is best 
seen in figs. 11, 11,iv. The neck passes gradually into the base and 
ends abruptly at the spiral. It is some 3 mm. long and 2 wide 
and thick. It has an angle along the ventral face that continues 
the ridge of the base up to the outer part of the spiral. 
The spiral or scroll may be likened to a long triangular plate 
with its edges rolled in together so as to leave a groove between 
them, but it is a plate some 8 mm. long, with the edges greatly 
thickened, so that the resulting mass is apparently solid. The 
groove begins on the median side, fig. 11, and passes in a sinuous 
course to the ventral side and along this diagonally to the very 
tip. The apparent bifid nature of the stylet is due to an out- 
growth from the median part, quite separate from the real end 
of the organ, in which the groove is continued through its entire 
length. We have then to describe a sinuous groove and its two 
boundaries, which we will call the median mass and the external 
mass; and also the two tips. The external mass, seen from the ven- 
tral side on the right of fig. 1, shows a proximal part about 2 mm. 
long and 1 mm. wide, bearing a marked ridge parallel to its sides 
and continued up from the neck. And then it suddenly turns at 
a large angle and becomes a rounded and gradually tapering ter- 
minal part, something less than $ mm. wide at first, and 6 mm. 
long. This passes behind the slender protuberance of the median 
mass to end as a flattened, horny tip together with the like ending 
of the median mass. In other words both external and median 
masses unite as the horny tip that we will call the canula. The 
sudden change in direction of the mass is accompanied by a like 
change in the groove whose edge it forms; this change of the groove 
we will call the angle of the groove. 
Seen from the outer face, fig. 1v, the external mass is widely 
swollen proximally, some 2} mm. deep, and gradually narrows into 
the distal part. The round canula is bent somewhat, ventrally. 
