25 



The nerves passing to the mandibles have their origin 

 on the anterior margin near the middle line. They 

 course along the muscles of the fpsophagus, and reach the 

 mandibles near the base of the mouth. 



The next pair of nerves arise at the anterior angle of 

 the ganglion, course forward, under the nerves of the 

 antennae and antennules, to the frontal plate which they 

 enter about midway between the lateral margin and 

 middle line. They then turn abruptly and pass out to 

 the lateral margins of the frontal plate, just above the 

 antennules. The margin at this point is destitute of the 

 transparent membrane which surrounds the carapace. 

 The nerves terminate in a shallow cup, evidently a 

 sensory organ. 



Three other pairs of nerves arise from the anterior 

 angles of this ventral ganglion. The first passes to the 

 rudimentary first pair of maxillae, the second, a short 

 nerve, passes to the second pair of maxillae, and the third 

 to the muscles controlling the lateral margins of the 

 cephalo-thorax. 



The nerves supplying the first pair of maxillipedes arise 

 from the anterior portion of the lateral margin. They 

 are large nerves at their origin, but immediately divide 

 into four branches, passing to the maxillipedes and 

 muscles. The second pair of maxillipedes are also supplied 

 by nerves arising from the lateral margins. Like those 

 of the first maxillipedes they have strong roots, and at 

 once divide into three branches Avhich pass to the second 

 maxillipedes and their muscles. 



The remaining nerves have their roots in the posterior 

 end of the ganglion. There are three pairs. These 

 supply the five pairs of feet and the abdomen. The outer 

 pair of nerves supply the first pair of feet. Near the 

 origin a branch is given off which passes to the muscles 



