278 E. A. ANDREWS 
the base of the first can one separate the two, as by that means 
the radius is brought to the orifice out of which it readily passes. 
When the two stylets have been erected by their own erector 
muscles and locked together by their muscular movements which 
lead to this mechanical fastening of the edge of the triangle within 
the groove, they form one organ, physiologically, which is to 
transfer the sperm without any further muscular activity within 
it. : 
The appearance of the two locked organs is indicated in the 
somewhat diagrammatic sketches 29, 30. In 29 the external view 
of the left stylets and part of the fifth thoracic legs is shown. The 
second stylet, to the right of the figure shows the solid tip region 
of the endopodite applied closely against the most protuberant 
part of the posterior face of the spiral of the first stylet, while 
the terminal flabellum runs along parallel to the canula and spatu- 
ula. In fact the tip of the bony endopodite seems to overlap 
the contours of the spiral and this is due to the soft nature of the 
depressed region of the median face of the end of the endopodite 
as is seen in fig. vit. The guide ridge is the part seen external to 
the spiral in fig. 29, while the soft surface is squeezed against the 
rounded face of the spiral and the triangle is applied close against 
the median face of the spiral so that it can be seen only from the 
median view. 
Turning to the median view we see, (fig. 30) the triangle lying 
over the neck and extending out along the groove. The elbow 
of the triangle lies over the orifice. The radial edge of the tri- 
angle conforms with the obliquity of the groove since both the 
wedge and the radius are firmly inserted in the groove. 
Figures 29 and 30, show the supporting fifth leg in section, as 
a rounded cross-hatched area. It will prevent the locked stylets 
from being shoved forward, or closed up against the sternum an- 
teriorly. It is also obvious that the movement backward toward 
a vertical position will be hindered, not only by the inclination 
and rigidity of the basal joint of the first stylet, but by a like join- 
ing of the base of the second stylet, since one cannot move back 
without the other, for the radius and wedge will go no further 
