146 
SIDNEY F. HARM KR. 
Fig. 8. — A regenerating specimen resembling tliose shown in figs. 4 
and 5, bnt more completely developed. Slide M. 
PLATE 8. 
Fig. 9. — A completely regenerated individual. The original tube 
has been subdivided by septa (s.), and the new distal end of the tube 
has been developed as a lateral outgrowth starting immediately on the 
proximal side of the septa. Slide Q. 
Fig. 10. — A small regenerating fragment in which the muscular part of 
the body-wall is unusually long; l., the commencing lophopliore ; l.m., 
longitudinal muscles. Slide M. 
Fig. 11. — The appearances of this specimen suggest that a small 
fragment produced by fission on the distal side of the septum (s.) has 
formed a new distal end to its tube by lateral outgrowth instead of 
making use of the original distal end of the tube. Slide P. 
Fig. 12. — Another small fragment. The muscular part of the body- 
wall (muse.) is already in vagina ted at its base (inv.) ; l., the commencing 
lopliophore. Slide N. 
Fig. 13. — A specimen with strongly marked invagination (inv.) of 
the proximal end of the muscular region (muse.) and a commencing 
lopliophore (l.). Slide M. 
Fig. 14. — A sagittal section passing medianly through the distal end 
of the body, inv., invaginated part of body-wall ; ep., epistome ; ces., 
oesophagus, separated by a circular valve from the proventriculus (pr.) ; 
an., position of anus. (Zeiss C Obj.) Slide F. 
Fig. 15. — A system of empty tubes from which the course of the 
transverse fissions of the animal can be inferred. For explanation see 
text, pp. 12, 20. Slide K 
Figs. 16-25. — From a series of sections transverse to the principal 
axis of the body of an adult specimen. (Zeiss C Obj.) 
Fig. 16. — Through the retracted tentacles, of which 22 are present, 
arranged in the form of a horse-shoe. Slide A 1 . 
Fig. 17. — The tentacles have united at their bases on the anal side 
(l .) ; ep., the tip of the epistome. Slide A 1 . 
Fig. 18. — A more proximal section; ep., epistome. Slide A 1 . 
Fig. 19. — The epistome (ep.) is cut at the level where it reaches its 
greatest size. Slide A 1 . 
Fig. 20. — The tentacles have completely united at their base, and 
the mouth (m.) is thus outlined. The anus (an.) lies between the 
lopliophore (l.) and a lobe of the metasome; n.r., part of the nerve- 
ring. Slide A 1 . 
