Pomona College, Claremont, California 79 



degenerate or else for some other purpose. The ganglia are con- 

 nected by their perineuria! sheaths in the mid line and the nuchal 

 sacks, though they do not fuse are separated merely by a thin 

 septum. They differ in this respect from Lumbriconereis erecta 

 Moore where the ganglia are quite widely separate. Histologically 

 the structure is much the same as the other ganglia of this form. 

 The cells are a little larger than those of the brain and the reticulum 

 is considerably more noticeable. 



The suboesophageal ganglion (Fig. 1; j) is of the usual annelid 

 form as is the nerve trunk (Figs. 8, 9). The segmental nerves are 

 given off one pair to each segment from a long narrow pedicle 

 (Fig. 3; k). They follow around the segment just outside the mus- 

 cular coat. At the base of the foot there is a small ganglion giving 

 off two branches, one to the foot, which branches twice and one 

 passing beyond the foot to the dorsum where it branches extensively 

 in both the epithelium and muscles. 



Visceral System. The visceral nervous system (Fig. 4), con- 

 sists of three \isceral ganglia, and a complex system of nerves serv- 

 ing the various pharyngeal muscles. The system originates in a 

 main visceral ganglion (Fig. 4; v). which is situated just below the 

 brain and is equipped with four pairs of symmetrical branches. 

 The front pair of ner\-e trunks are short and rather thick. They 

 lead to the lateral halves of the brain and their fiber masses fuse 

 with the "punkt-substanz" of this part of the brain. The side 

 branches leave the visceral ganglion at about its central and widest 

 part and lead to the base of the oesophageal connectives. Near 

 where these nerves leave the visceral ganglion a pair of small nerves 

 (Fig. 4; r) about .01 mm. in diameter branch off from the ventral 

 side and extend caudad for a distance of about 2.5 mm. These 

 nerves form an analogue of the complex labio-visceral nervous sys- 

 tem found in Eunice. (Quatrefages; '44.) The two hind trunks 

 branch out into the visceral nervous system proper, as diagrammed 

 (Fig. 4). They go straight back, parallel, assuming a diameter of 

 about .04 mm. About 1 mm. behind the visceral ganglion they 

 branch into an outer (F'ig. 4; m) and an inner pair (Fig. 4; u). 



The outer pair form the maxillary nervous system. They bend 

 \entrad and branch in a \ery complex manner on either side of the 



