No.2. ] ANURIDA MARITIMA. 227 
irregular in shape. These eggs are not spherical nor even oval, 
but angular and compressed so as to entirely fill the abdominal 
and even part of the thoracic cavities. The number of eggs in 
a single individual varies from twelve to twenty; among the 
large mature eggs, which appear as masses of yolk, there are 
numerous small, immature ova, and in certain places masses of 
germinal epithelium. 
Taking a stage where the eggs are less mature and yolk 
formation less advanced, the structure of the ovaries can be 
made out definitely. The organs are composed of a pair of 
simple tubes placed one on each side of the alimentary canal, 
as described by Fernald (90). These are prolonged anteriorly 
into two long filaments, which reach into the second thoracic 
segment and finally coalesce with the fat body on each side at 
about the level of the middle of the alimentary canal in the 
vertical plane. Posteriorly the tubes retain their paired condi- 
tion to the end of the fourth abdominal segment; at this point 
the tubes unite and form a single receptacle that may be called 
the uterus. This shortly passes into the oviduct, which is a 
median and unpaired opening at the hinder end of the fifth 
segment, and then directly to the ventral surface of the animal. 
Below this oviduct, as described by Fernald (90), is a small 
sac opening to the outside by a common opening with the 
oviduct, which may be a receptaculum seminis; but careful 
search in many stages failed to reveal the presence of any 
spermatozoa. 
Fig. 1, Pl. XX, is a longitudinal section through an ovary 
in which the eggs are just beginning to accumulate yolk; it 
shows the cephalic elongation, egg masses, and germinal 
epithelium. Nothing of the unpaired uterus and duct can be 
seen as the section passed to one side of these parts. 
Four different structures are clearly shown. First, the 
cephalic elongation (Fig. 1, c.e/.), which runs into a fine point 
and is attached laterally to the fat body lining the thorax. 
The structure of the thread is shown in Figs. 1,5, and 6. It is 
a fine membrane in which nuclei are irregularly placed. These 
nuclei have no germinal characters; they are not to be dis- 
tinguished from the nuclei of the wall of the ovary. This 
