W. A. JIarding 187 
is sometimes split up into subsidiary wrinkles. This feature may be due to con¬ 
traction in alcohol. 
The large and prominent anus lies in the 102nd annulus, causing it to become 
double [Fig. 4], 
The genital apertures are five rings apart, small and difficult to see. The male 
orifice lies between the 31st and 32nd annuli ; the rather larger female orifice lies 
between the 36th and 37th annuli. 
The horizontal lines connecting the figures define the annulations which are numbered 
1—9 in the middle figure (anuulation 1, indicated by a broken line, was indistinct). 
Fig. 4. Dorsal aspect of posterior rings and acetabulum. 
Fig. 5. Diagram of ventral surface of anterior sucker. 
a. Outer lip. 
b. Its inner, crenulate border. 
c.c. The diverging ridges. 
d. Edge of mouth with frilled membrane. 
e. Interior of pharynx. 
f. Cut edge of body, opened by a median ventral incision. 
The general characteristics of the leech indicate that the complete somite is com¬ 
posed of five annuli. As no segmental papillae or nephridial pores can be detected 
[owing to immersion in alcohol ?] it is impossible to determine this point with 
certainty from external examination. 
