APPENDAGES AND NERVOUS SYSTEM OF APUS CANCRIFORMIS. 371 
Fie. 2.—Diagram of the anterior portion of the nervous system of Apus 
cancriformis seen from below (constructed from Zaddach’s figures), 
C. Archi-cerebrum. 
@. @sophagus. 
G.1. First post-cerebral ganglion. 
G. 2. Second post-cerebral ganglion (ganglion of the mandibular seg- 
ment). 
G.3. Third post-cerebral ganglion (ganglion of the maxillary segment). 
G. 4. Fourth post-cerebral ganglion (ganglion of the first thoracic seg- 
ment). 
I an'. Nerve to the first antenna. 
IT an. Nerve to the second antenna. 
TIT mn. Nerves to the mandible, 
IV mz. Nerves to the maxilla. 
V mp. Nerve to the maxillipede. 
VI th’. Nerves to the first thoracic appendage. 
x. Frontal nerves. 
oc. Nerve to the left eye. 
@g. (sophageal ganglion impar. 
@s, Posterior cesophageal nerve. 
to fuse with neighbouring ganglia of the same side, ‘This ten- 
