22 G- O. Sårs. 



partly concealed by the ocular muscles. From the some- 

 what projecting lower corner of the cephalic ganglion, a thin 

 nerve passes forwards to the ocellus, forming around it a 

 ganglionic swelling, and to each side another very delicate 

 nerve is sent off, which curves upAvards, and is dissolved into 

 numerous fine fibres, each ending with a ganglionic swelling 

 inside the dorsal face of the cephalic shield, between the 

 eye and the protractor-muscles of the antennae. The anten- 

 nular nerves originate from the posterior part of the gang- 

 lion, and extend forwards, at a short distance from the ventral 

 edge of the head, to the rostrum, where they enter the an- 

 tennulæ, forming within their distal part a rather large gang- 

 lionic swelling, from which are sent off nerve-fibres to the 

 apical olfactory papillæ (comp. Pl. II, fig. 12). Behind, the 

 cephalic ganglion is continued in the large œsophageal com- 

 missures, which, after having crossed the œsophagus, curve 

 abruptly behind, to form the nervous chords belonging to 

 the trunk. At this curvature, 2 strong nerve-stems are sent 

 off upwards from each commissure, and enter the base of 

 the corresponding antenna. The subsequent course of these 

 nerves I have not been able to trace, owing to their being 

 concealed by the strong muscles filling up the stem of 

 these organs. The nervous chords belonging to the trunk 

 are also very difficult to examine; but it is very likely 

 that they agree in structure with those in other Branchi- 

 opods. 



The ovaries may be easily traced on each side of the 

 intestinal tube, extending through the greater part of the 

 trunk. They are of somewhat irregular form, and in parthe- 

 nogenetic specimens (see PL I, fig. 1) contain several rows 

 of ovarial cells in different stages of development, some 

 filled with a clear greenish yolk-mass. In gamogenetic spe- 



