2Ó2 



I. 1KEDA. 



ness and the irregularity of the 

 course taken by the fibres, the 

 muscle as a whole appears shiny. 



Blood vessels. — The vascular 

 system is in general the same as in 

 other Echiuroids {e.g., Thalassema 

 and lioncllid). In the body 

 proper there occur two principal 

 longitudinal vessels, i.e., (i) the 

 ventral vessel (fig. 2, vv) along the 

 ventral nerve-cord (vn) and (2) the 

 dorsal vessel (dv) extending between 

 the proboscis basis and the " heart " 

 (lit) which embraces the posterior 

 Fig. 3.— Magnified view of the radices of the part of the fore-gut. The " heart " 



ventral hooks together with the radial muscles. 



avy, oJ, rm, vn, and vv, same as in fig. 2; im and the ventral vessel are connected 

 — interbasal muscle,/// — pharynx. 



to each other by a short vessel or 

 neuro-intestinal vessel (niv), which originates about 2 mm. behind the 

 insertions of the ventral hooks. A little anterior to the above spot there 

 arises another more slender branch which runs forward beyond the 

 interbasal muscle and is finally embedded in the proboscis (see avv in 

 figs. 2 and 3). Anteriorly this accessory ventral vessel, if I may so call 

 it, joins the ventral vessel at a point where the latter enters the 

 proboscis. 



Sexual gland. — The position of the sexual gland is as in other forms, 

 i.e., along the dorsal line of the posterior part of the ventral vessel.* It is 

 a moniliform string about 5 mm. long. As the specimen is a female, the 

 gonad is made up of a great number of variously sized ovarian eggs (fig. 

 4). The youngest eggs are clustered on the ventro-lateral side of the ovary, 

 but more on the ventral side where the germinal epithelium passes over the 

 peritoneal covering of the ventral vessel. The remaining surface of the ovary 

 is thickly studded with more or less advanced oogonia (fig. 4). The 



* The gonad is represented in fig. 2 in an unnatural position lor the reason before mentioned. 



