146 



The system (PI. VIII, Fig. 13) consists of two principal longitudinal 

 vessels, one dorsal and one ventral, and transverse vessels which con- 

 nect them in the anterior region. The dorsal vessel arises from the 

 perivisceral sinus in XIII-XIV. An examination of twenty speci- 

 mens showed that the origin of this vessel is not constant in position 

 and that it varies within the limits of XIII-XIV. In the majority of 

 cases the origin is at XIII/XIV. In the intersegmental regions this 

 vessel shows constrictions which are slight in its anterior part but dis- 

 tinct in its posterior half. Distinct swellings are present in XI, XII, 

 and XIII. From its origin the dorsal vessel extends cephalad, parallel 

 and dorsal to the digestive tract, and throughout its course it main- 

 tains a rather close relation to it. In I this vessel divides into two 

 symmetrical branches, one of which passes around the right side and 

 the other around the left side of the digestive tract. These branches 

 extend to the ventral side of the buccal cavity and each comes to lie 

 parallel to it, thus forming the right and left ventral trunks. They 

 extend caudad into IV, W'here they approach each other and unite, thus 

 forming a single vessel which extends to the posterior region of the 

 body. In III a branch extends dorsad from each of the ventral vessels 

 to connect with the dorsal vessel at a corresponding point, thus form- 

 ing the first pair of transverse vessels. The second pair of transverse 

 vessels is in IV, anterior to the point of union of the two ventral 

 vessels. The third pair is united with the ventral vessel very near 

 IV/V and immediately posterior to the point of union of the right 

 and left ventral vessels and extends to the dorsal vessel, uniting with 

 the latter near the corresponding point of union of the second pair 

 of transverse vessels. The fourth pair connects the dorsal and the 

 ventral blood vessels in V. 



Ncphridia. — The nephridia (PI. IX, Fig. 15) are of the usual 

 lumbricillid type in which the postseptal part is greatly developed but 

 the anteseptal part is represented only by the nephrostome. The ef- 

 ferent duct arises from the ventral surface of the posterior end of the 

 postseptal part, and opens to the exterior in front of the ventral setae. 



Testes. — The testes are in the usual position in XI and are multi- 

 lobed. Each lobe is clul>shaped, and its attachment to the ventral 

 surface of X/XI is very slender. There are approximately 8-10 of 

 these lobes on each side of the digestive tract, all somewhat similar 

 in size and shape, and radiating fanwise from the point of common 

 attachment, the anterior and the posterior ones extending out into the 

 adjacent somites. Each lobe is capped by a sperm sac. 



Spenniducal Funnel. — This organ (PI. IX, Figs. 14, 17) lies in 

 the usual position in XL The length is about four to five times the 



