180 
This layer is a syncitium containing regions of longitudinal and of cir- 
cular fibres but the individual fibres of this layer do not:represent cells. 
This syncitium is supplied with two rows of nuclei which extend the 
length of the body. These nuclei are paired so that a cross section 
through the body might show a nucleus in the muscle layer on either 
side of the dorsal longitudinal canal. These are so regular in arran- 
gement that in no case could more than two muscle nuclei occur in a 
single cross section of the body. 
The lemnisci are short, never extending much beyond the end of 
the proboscis receptacle when the proboscis is protruded. Their average 
length is about 0,5 mm. These are not bilaterally paired organs but 
arise as two sacs in the anterior end of the body, one dorsal and the 
other ventral in position. The dorsal lemniscus bears two nuclei while 
the ventral possesses but a single one. 
The proboscis receptacle is a sac consisting of a single muscular 
layer extending from the base of the proboscis into the body cavity for 
a distance of 0,4—0,6 mm. From the rounded base there extend 
posteriad two long retractors of the receptacle which find attachment 
one on the dorsal wall and the other on the ventral wall of the body. 
These retractors of the receptacle are direct continuations of the pair 
of muscles within the proboscis called the invertors of the proboscis. 
Within the proboscis receptacle is located the brain which is triangular 
in lateral aspect with the base of the triangle attached to the ventral 
wall of the receptacle near the posterior end of the latter. The brain 
has a length ranging from 0,085—0,100 mm., with a maximum breadth 
of 0,035—0,040 mm. 
The testes, two in number, are slightly elongated oval bodies 
lying one anterior to the other in the midst of the body cavity of the 
male. The anterior testis has an average length of over 0,30 mm. and a 
breadth of about 0,17 mm., while the posterior testis is considerably 
shorter, being only 0,24 mm. long, but having a breadth equal to that of 
the anterior testis. The cement gland is a compact mass just posteriad 
to the posterior testis. The posterior margin of this gland is hollowed 
out to receive the reservoir of the cement gland. The average length of 
the cement gland is 0,238 mm, with a range of variation from 0,170— 
0,400 mm. in different individuals. It has a dorso-ventral depth 
varying from 0,150—0,260 mm., with an average of 0,200 mm. The 
eight large nuclei with their approximately uniform distribution through- 
out the gland, are typical for this species. Cement reservoir is the name 
given to the spherical body filling the posterior emargination of the 
cement gland. It has a diameter of 0,108 mm. A very short tube con- 
nects this reservoir with its gland. This duct proceeds from the poste- 
