176 ARTHUR WILEY. 
mentioned of the relative scarcity of the females in compari- 
son with the males, I draw three provisional conclusions: 
firstly, that during the process of reproduction (fecundation 
Fic. 21.—Female genital organs of N. pompilius, seen from below, to 
show the direction in which the polar areas of the ova lie. yp. a. Polar areas of 
ovarian ova. o. a. Aperture of ovarian sac. g. Uterine portion of oviduct. 
v. Vaginal portion of oviduct. 
and spawning) the females live in retirement; secondly, that 
the females practise what the Germans call ‘ Brutpflege;” 
and lastly (what I regard as almost certain), that repreducues 
takes place all the year round. 
(3) Cephalic Arteries (Figs. 22 and 23).—For a descrip- 
tion of these arteries it will suffice to refer to the explanation 
of the figures. I will, however, call attention to the varia- 
bility of the right and left anterior proventricular arteries ; 
the latter was absent from the individual represented in fig. 7. 
The two main trunks into which the dorsal aorta divides be- 
hind the brain may be called the right and left innominate 
arteries. 
It is a singular fact that the great median buccal artery 
always springs from the right innominate artery. The con- 
stancy of this origin would seem to indicate that it is poten- 
tially a paired structure. 
