COE: TERRESTRIAL NEMERTEAN OF BERMUDA. 545 
canals from the cerebral sense organs lie somewhat ventral to the 
posterior ends of these grooves, and in nearly the same transverse 
section. They have, however, no connection with the grooves and 
in this respect differ widely from those of the Heteronemertea. 
The frontal organ, in this form so remarkably developed as an 
outlet for the secretions of the cephalic glands, is also almost cer¬ 
tainly to be placed among the sense organs. This frontal organ is 
described above in the discussion of the cephalic glands and is 
represented in figure A. 
Reproductive Organs. 
As has been mentioned above, great variation exists in the state 
of development of the sexual products in different individuals col¬ 
lected in the same locality and at the same season of the year. In 
June and July, 1903, the majority of the larger individuals contained 
embryos in a well advanced stage of development. Somewhat 
smaller specimens contained ova of various sizes, but were without 
spermaries or embryos, and must consequently be considered as 
representing the female phase of sexuality, or as females for the 
time being. Those ovaries which had nearly mature eggs were 
provided with distinct ducts leading to the exterior of the body. 
Such ducts are wanting, however, in the worms containing embryos. 
It is therefore reasonable to assume that an efferent duct is formed 
at the time of maturity of the ova in each ovary and that this duct, 
after allowing entrance for spermatozoa which fertilize one or more 
of the contained ova, is obliterated by a closing together of the body 
walls. The eggs thus fertilized then develop into embryos which, 
on completing their development into young worms, rupture the body 
walls and make their escape from the body of the parent. 
Specimens collected by Professor Verrill in April, 1901, contained 
immature ova only, although the ovaries already had ducts leading 
into the muscular layers of the body and in some instances quite 
through to the exterior. 
It is a remarkable fact that in midsummer many of the larger 
worms which were filled to the point of rupture with very large 
embryos contained in addition both ovaries and spermaries of 
small size. It is still more remarkable that although the eggs in 
such individuals were always very immature, yet the spermaries 
