410 
EDWIN S. GOODRICH. 
The Genital Organs of the Male. 
No correct account has yet been given of the very interest- 
ing genital organs of the male Nerilla. It has already been 
mentioned that ordinary nephridia do not occur in segments 
6 , 7, and 8. In these three segments are developed 
three pairs of sperm-ducts, all converging to a common 
pore at the posterior limit of the seventh segment (figs. 
10, 19). We shall discuss below whether these ducts are 
modified nephridia as suggested by de Beauchamp (2). Miss 
Pereyaslawzewa saw the median pore, but thought the sperm- 
cells were developed in the wall of the gut, and apparently 
mistook epidermal glands for parts of the testes (13). 
The six sperm -ducts are of similar structure, but of varying 
lengths, the first pair being by far the longest. Each consists 
of a slender tube of uniform thickness and a coelomic funnel. 
The inner wall of the tube is clothed with closely set, fine, 
short cilia working towards the external pore (fig. 12). 
Pieicing the septum, the duct widens out into a funnel 
which opens into the segment in front. The funnel consists 
of a few symmetrically disposed cells, bearing numerous fine 
cilia on the surface of the septum (figs. 12, 22, 24). The six 
spermiducal funnels lie, then, on the septa between segments 
-5 and 6, 6 and 7, 7 and 8, opening into the coelom of seg- 
ments 5, 6, and 7 (figs. 10, 19). 
The six sperm-ducts converge to a common chamber lying 
in the middle line at a point where the ciliated groove is 
interrupted (figs. 6, 24). 
This median chamber, or genital atrium, also ciliated, is 
blind in front, but opens behind by a pore, the edges of which 
are drawn out on each side to form two small processes. I 
believe these to serve for copulation, but have not observed 
them in action. 
The copulatory processes are formed as epidermal out- 
growths, and are not ciliated. Backwards from the genital 
pore the ventral ciliated groove resumes its course. Special 
