No. I.] THE METAMERISM OF AEPHELIS. 59 



annelids. In Nephelis, I have found it to be much more 

 extensive than has been figured in any anneUd that has come 

 to my notice. 



It arises in Nephelis very similar to the method figured by 

 Leydig (/. c.) for Haemopis vorax Brandt (PI. IV, Fig. 5). In 

 this latter leech Leydig shows the sympathetic system lying on 

 the walls of the " crop," but not connected with the part arising 

 from the collar. In Nephelis (PI. VII, Fig. 17) the junction 

 between the two systems is on the median side of the collar 

 near the nerve root I-II. A fibrous projection from the anterior 

 side of the collar on each side gives rise to three branches 

 which run over the wall of the oesophagus ; the dorsal and 

 ventral roots pass off in a —| fashion, while the lateral root 

 comes off from the median side. Six capsules, three on either 

 side, contain nerve cells whose processes run into these 

 branches. One pair (PL VI, Figs. 1 1 and 13, symp.), the larger 

 of these capsules, is on the collar, the other two on the posterior 

 side of the dorsal branch. The ventral branches retain their 

 individuality for some distance as they approach the mid- 

 ventral line, but they soon become lost in a system of closed 

 meshes. The lateral branches continue as such, plainly taking 

 part in forming the meshes, but preserving their identity 

 throughout (PL VII, Fig. 17; PL VIII, Fig. 19). 



The dorsal branch of each side rises parallel to the collar, 

 just in front of it. Professor Patten has called my attention to 

 the fact that this structure in this position is comparable to a 

 similar structure in Limulus. A narrower band connects them 

 in the mid-dorsal region so that they form together a half circle. 

 Two branches pass backward near the median plane into two 

 large ganglionic masses lying just under the collar (PL VIII, 

 Fig. 20). All these branches give off bundles of fibers that 

 run forward to the buccal cavity, and these bundles differ in 

 two ways from the plexuses behind the collar. They contain 

 but few, if any, cell bodies, being processes of the cells that lie 

 clustered together in ganglionic masses between the fibers and 

 the meshwork of the plexuses on the oesophageal walls. Fig. 

 20 shows this as it occurs on the dorsal side. It is a dorsal 

 view drawn from a Haller preparation and, hence, shows no 



