MiMONECTES, A REMARKABLE GENUS OF AmPHIPODA HyPERIDEA. 5 



The middle part of the ganglion seems to be the optical part 

 of the nervous mass, as fine slender nerves issue from it forwards to the 

 foremost ocelli. The fine nerves going to the other ocelli seem to arise 

 from the commissural cords, connecting the cephalic ganglion with the 

 infraoesophagial ganglion, but pe';haps this only seems to be so, the 

 fibres really coming in a stem or cable from the central part of the 

 ganglion and branching off successively one after the other from the 

 common stem along the side of the commissure. However this may be, 

 it is certain that each of these slender nerves runs to one of the ocelli 

 and enters it, being a little thicker or more swollen at the point of en- 

 trance. The number of such ocelli is from eight to ten on each side 

 of the head. The third or posterior pair of lobes are nearly as large as 

 the anterior, and directed obliquely forwards. A portion of the nerve 

 originating from the lobe runs to the peduncle of the superior antennas, 

 another portion goes to the region of the mouth. The principal nerves 

 of the mouth come however from the infraoesophagial and the first pe- 

 reional ganglion. 



The commissural cords, connecting the cephalic and the infraoeso- 

 phagial ganglia, are very stout and thick. The infraoesophagial gang- 

 lion is coalesced with the first ganglion of the ventral chain. From 

 this ganglion, which is not divided longitudinally in the middle into two 

 portions, arise two pairs of nerves; the first pair run to the mouth, 

 the second upwards to the interior of the head. From its hinder part 

 issue the two commissural cords, widely separated at their base, but 

 close together at their entrance into the ganglion of the first pereional 

 segment. This ganglion, as well as the five next following ones, is com- 

 posed of two distinct ganglia, pressed against each other, but not coa- 

 lesced. The inter-ganglial parts of the chain, or the commissural cords, 

 are more widely separated. The two lateral ganglia of the seventh pe- 

 reional segment are totally fused together, so as to form one nervous 

 mass. From every one of the seven ganglia, which form the nervous 

 chain of the pereion, two pairs of strong nerves issue, the anterior pair 

 running to the legs and gills, the posterior upwards to the organs of 

 circulation. From these last nerves branches run up to the walls of the 

 globular bladder, but only in the second, third, and fourth segments. 

 From the commissural cords, between each pair of ganglia, long slender 

 nerves branch off, one on each side; they run to the sides of the cor- 

 responding segment. The ganglionic chain continues backwards in the 

 pleon with three pairs of large ganglia, but, as in the last pereionial 



