86 ALFRED GIBBS BOUENE. 



figs. 6 and 7 a. The relation of these long capillary setse to 

 the branchial processes is described above. The other kind of 

 seta occurring in the dosal bundle is always of the same length, 

 and has a curved sickle-shaped free extremity (fig. 6). Such 

 setae do not occur in the more anterior bundles, and in passing 

 backwards one comes across intermediate conditions between a 

 short straight capillary seta and the sickle-shaped form figured. 

 As a rule, there are two or three straight and two or three 

 curved setee in each bundle. 



The ventral setae are all '^ crotched-shaped;" in the most 

 anterior segments the free extremity has the shape drawn in 

 fig. 7 h ; but this, in going backwards, soon passes into the 

 shape shown in fig. 7 a. Each of these ventral setae has a little 

 swelling placed rather nearer to the free extremity than to the 

 root. There are four to six setae in each ventral bundle. All 

 the setae diminish rapidly in size as one approaches the poste- 

 rior extremity, which presents therefore, as in Naids, the 

 appearance of being a region of continued growth. 



Viscera. — The alimentary canal presents no special feature 

 of interest ; there is no enlargement corresponding to the so- 

 called gizzard of many Naids. 



The coelom is, as in most Oligochaeta, incompletely divided 

 into a series of chambers by diaphragms placed between the 

 segments. 



The coelomic corpuscles are rounded (fig. 8), and like those 

 of Naids. They contain numerous olive-green granules, which 

 look like droplets of fatty matter. They may be seen passing 

 from segment to segment, and at times into the branchial 

 processes. 



The circulatory system consists of a dorsal and ventral 

 vessel and a series of lateral vessels, a pair in each segment, 

 which run from the dorsal to the ventral vessel, and in those 

 segments provided with well-developed branchial processes 

 loop out into the process (fig. 2). 



The walls of the dorsal vessel are much pigmented, as in 

 many Oligochaeta, while those of the ventral vessel, and, as a 

 rule, the lateral loops, are unpigmented. 



