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EXPLANATION OP PLATES XI.-XIII. 
a.xjJt = ampulla of spermatheca. 
(It — atrium. 
b = bulb of spermatheca. 
cp = internal epithelium. 
pep = peritoneal epithelium. 
/ — funnel of sperm duct. 
m.f! = muscular sac ( = autospermatheea of Phreodriloides). 
p = penis. 
p.s = penial sac. 
spt.d = spermathecal duct. 
sp.g = spermiducal gland. 
r.rZ = sperm duct. 
Fig. 
1. Diagrammatic lateral view of spermathecal and male genital apparatus. [The lining 
of the penial and muscular sacs is not to be interpreted from that represented in the 
figure {vide figs. 4 and 8).] 
2. Ground plan of the same apparatus. 
3. Wall of spermiducal gland. 
4. Section through penial and muscular sac, so as to pass through the entrant point of the 
spermathecal duct. 
5. Section through the ampulla and bulb of spermatheca, showing the spermathecal duct 
within the bulb. 
6. Section through spermathecal duct. 
7a 7b, 7c. Series of sections showing the relations of spermathecal duct, bulb, and 
ampulla inter se. Sections 7a and 7b are cut obliquely, and so show the ampulla. 
Section 7c is strictly transverse through the bulb. Sections 7a and 7b are 
consecutive. 
8. Part of wall of penial sac. 
9. Photograph of section showing the male pore, penial sac and muscular sac. Note the 
muscular sac behind and to the left of the penial sac, with which it is not con- 
tinuous in this section. 
