~ 
ordinary length and power, which pass obliquely back- 
ward to the lateral margins of the carapace nearly opposite 
the first pair of feet. The muscles of the first maxille 
are very short and thin. They pass along the posterior 
surface of the muscles of the antenna, to the lateral 
margins. The second maxille are controlled by powerful 
muscles passing to the lateral margins. The muscles of 
the first maxillipedes pass obliquely forward to the lateral 
margins. The second maxillipedes are supplied with short 
and powerful muscles which pass forward under the 
second maxilla. The terminal claw is, provided with 
muscles of great strength. The first three pairs of feet 
are supplied with a complicated series of muscles passing 
dorsally amongst those controlling the posterior portion 
of the cephalo-thorax. The fourth pair of feet are 
apparently little used, and consequently are only supplied 
with feeble muscles. The alimentary canal is controlled 
by longitudinal muscles, and also by muscles passing 
transversely, which produce the wave-like peristallic 
motions and crenated appearance. The anus is opened 
and shut by muscles passing obliquely, which open and 
shut each side alternately or simultaneously according to 
the requirements of the animal. The reproductive organs 
are also controlled by muscles, which give rise to pulsating 
movements, and assist in expelling the ova and 
spermatophores. 
Tue NerRvous SYSTEM. 
The central nervous system in Lepeophthevrus consists 
of a cerebral or supra-cesophageal ganglion and a large 
sub-cesophageal ganglion placed on the ventral surface, 
in the median line, and extending from slightly in front 
of the second pair of maxille to near the articulation of 
the second pair of maxillipedes with the body. The 
