NO. 4 HARTMAN : POLYCHAETOUS ANNELIDS 443 



neuropodia but slightly nearer the former; in abdominal segments they 

 are somewhat larger but they continue to occupy a position between the 

 dorsal and ventral branches of the parapodia. 



Parapodia are inconspicuous in the thorax except for the spreading 

 setal fascicles; in the abdomen they are conspicuous largely because of 

 their swollen glandular bases. In the anterior half of the thorax they are 

 about midway along the segmental length; farther back they move 

 progressively back so that they come to lie on the posterior third of the 

 segmental length. In branchial segments the tori are located just in front 

 of the segmental grooves. 



The second, or first setigerous, segment is provided with a pair of 

 small notopodial fascicles; the next 15 or 16 segments are complete with 

 both notopodia and neuropodia. The following one is transitional in 

 that the neuropodium is slightly glandular and contains both pointed 

 setae and long-handled hooks or only hooded hooks, resembling those 

 farther back. This difference between individuals is not correlated with 

 sex or with locality since in some instances (station 1450-42) individuals 

 of both kinds occur in a single collection. The pointed setae in this 

 transitional segment number only 2 or 3 ; they are located in the superior 

 part of the fascicle (see chart). 



Nephridial apertures are not conspicuous but can be distingiu'shed in 

 the segmental furrows, already present between the seventh and eighth 

 segment; they are continued posteriorly through segments 19 and 20, or 

 after the transitional one; they number 12 or 13 pairs. In some indi- 

 viduals the external pore is not visible before the eighth segment so that 

 the total number may be diminished by one. Nephridia have not been 

 distinguished in the abdomen. 



Abdominal tori are comparatively conspicuous largely because of 

 their thickened, glandular ridges. The first few pairs of notopodial tori 

 are separated from each other middorsally but by the fourth or fifth pairs 

 they appear to meet each other middorsally. They are well developed 

 throughout the middle and posterior segments but far back they decrease 

 in length and size and are more or less restricted to the dorsoectal portion 

 of the segment. Neuropodial tori are similarly well developed, their 

 length even greater than that of the notopodial ones; midventrally the 2 

 of a pair are separated by a smooth space. 



Branchiae are limited to posterior segments and are continued to the 

 posterior end. They consist of tufts of 6 to 12 palmately divided fila- 

 ments and arise from the posterior flange of the notopodial ridge. The 



