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PACIFIC SCIENCE, VoL XXII, July 1968 
s.d. sv ' P- BP- 
Fig. 3. Emprosthopharynx rasae. Sagittal view of copulatory organs. t a.f., Antrum femininum; a.m., 
antrum masculinum; p., prostatic organ; p.p., penis-papilla; s.c., ''shell” chamber; s.d., sperm-duct; s.v., 
seminal vesicle; v.i., vagina interna, containing eggs. 
into a relatively stout, conical, penis-papilla, 
which occupies much of the antrum mascu- 
linum. 
The ovaries are very much larger and more 
numerous than the testes. They lie dorsally to 
the testes and are distributed in the area between 
the cerebral organ and the copulatory com- 
plexes and extend into the submarginal regions 
of the body, thus having a greater area of 
distribution than the testes. The female genital 
pore lies immediately behind the male opening. 
It opens into a simple vagina, which extends 
antero-dorsally, but above the male antrum it 
turns sharply and runs posteriorly for a short 
distance. The antrum femininum (or vagina 
externa) is very short, while the ''shell” 
chamber (vagina media) is relatively long, 
extending to the dorsal curve. The "shell” 
chamber is lined with a tall glandular epithe- 
lium. The "shell” glands are numerous, sur- 
rounding the "shell” chamber and forming a 
pair of ala-like areas extending out from the 
chamber on both sides. The posteriorly directed 
portion of the vagina (the vagina interna) is 
short, and into its inner end open a pair of 
uterine canals. These canals extend anteriorly 
on both sides of the seminal canal to the 
pharyngeal region of the body. 
Hitherto, only three species of the genus 
Emprosthopharynx Bock, 1913 have been re- 
corded: E. opisthoporus Bock, 1913, from the 
Galapagos Islands and Panama; E. vanhopfeni 
Bock, 1931, from the Cape Verde Islands and 
Morocco; and an "extremely minute” and un- 
determined species of this genus mentioned by 
Bock (1925:61) from the Gilbert Islands. 
The species described here differs from E. 
opisthoporus in possessing fewer cerebral and 
tentacular eyes, in having an elongate and not 
a bulbous seminal vesicle, and in the fact that 
the sperm canal is not bifurcated in the hinder 
half of the body, as it is in the latter species. 
E. vanhopfeni is clearly very closely related to 
the present form but may be differentiated 
principally by its smaller size, by the distribu- 
tion and greater number of eyes, and by the 
presence of a penis stylet. 
It is interesting to note that the specimens 
of E. opisthoporus recorded from Panama by 
Bock (1925:61) were found in the "houses” 
of the pagurid Petrochirus caliporniensis from 
two different localities. Unfortunately, these 
specimens were not described morphologically, 
