DANFORTH: NEW PTEROPOD. 
13 
The gonad (pi. 2, fig. 6, g) is situated in the posterior part of the 
body, chiefly on the right of the intestine. It has the general form of a 
tube and develops sperm from the inner and eggs from the outer side of 
its wall. There is, however, an area next to the stomach where eggs 
do not seem to be developed. The sperm is matured first, and with its 
growth the cavity of the gonad becomes distended until the organ fills 
c r lie cr nc nu ejl 
Text-fig. A. — Horizontal section showing a portion of the gonad with 
developing egg follicles, hw, body wall; cr, chromatin mass; 
ecl,ec 2, ec 3, egg cells; ef l,ef 2, egg follicles; nc, nucleolus; 
nu, nucleus ; s, sperm ; si, stomach. 
the greater part of the posterior third of the animal. Figure 11 (pi. 4) 
is from a section of a specimen where the sperm is just beginning to 
ripen. Other specimens show the sperm in later stages as a deeply 
staining mass free in the cavity of the gonad. Text-figure A shows 
