New Turbellarian Associate of Hermit Crab — Prudhoe 
409 
it has been ascertained that the differentiation 
of a submarginal zone is due to the presence of 
numerous subcuticular gland cells, which open 
on the ventral surface of the body. These cells 
appear to contain a material that is deeply 
stained by eosin, and when secreted onto the 
ventral surface of the body it probably has 
adhesive properties. 
The mouth opens into the middle region of 
the pharyngeal chamber, which is very small, 
measuring only about 0.6 mm in length in the 
larger specimens. The pharyngeal chamber lies 
immediately behind the cerebral organ and 
shows no indication of possessing lateral 
pockets. It opens into a backward directed in- 
testine, situated in the median line and extend- 
Fig. 2. Emprosthopharynx rasae. Anterior region 
of body, showing arrangement of eyes and distribu- 
tion of ovaries and testes, o., Ovaries; t., testes. 
ing into the hinder region of the body. 
Throughout its length, the intestinal trunk bears 
numerous lateral branches which divide but do 
not appear to anastomose. 
The male genital pore is situated near the 
hinder extremity of the body, and the male 
copulatory complex lies entirely in front of it. 
The testes are small and follicular, and occur 
only in the ventral parenchyma, adjacent to the 
subepidermal musculature. They are distributed 
in the median and submedian fields from about 
the level of the pharynx to near the copulatory 
complex. They open into a common sperm duct 
which lies in the median line, ventrally to the 
intestinal trunk. This sperm duct extends from 
a short distance behind the pharynx into the 
hinder region of the body. It has thin walls 
and opens into a seminal vesicle. The latter is 
elongate, has thick muscular walls, and is lined 
with a ciliated epithelium. Although sperm is 
massed in the common sperm duct, none is 
present in the seminal vesicle. A short ejacula- 
tory duct runs from the seminal vesicle to open 
into the prostatic organ, which is a little larger 
than the vesicle. The prostatic organ is pyriform 
and possesses a thick muscular wall investing a 
tall glandular epithelial lining. This lining is 
smooth, as in other members of the genus 
Emprosthopharynx. Passing through the muscu- 
lature of the prostatic organ and opening into 
its epithelium, there are several collecting tubes 
of unicellular glands lying in the surrounding 
parenchyma. The prostatic organ opens directly 
