1903.] 



OLIGOCH.ETA FROM NEW ZEALAND. 231 



Letters used on the Figures. 



l.m., longitudinal muscles. 

 ne.f., nepliridial funnel. 

 ne.o., nephridiopore. 

 o.d., oviduct. 

 (£S., (Esophagus. OBS.', oesophageal 



opening of spermatheca. 

 ov., ovary, 

 septum. 



am., ampulla of spermatheca. 



at., atrium (spermiducal gland). 

 at.ep., atrial epithelium. 



bl., blood-sinus in wall of intestine. 

 h.w., body-wall. 



c, ciliated epithelial cell. 

 c.ep., ccelomic epithelial nucleus. 



chl., chloragogen cells. - , - , , , 



c.»,.., circular muscles. «.^?., septal gland. 



com., commissural blood-vessel. s.i.v., supra-intestinal blood-vessel, 



cop., copulatory chata), or sac con- sp.d., sperm-duct. 



tainino- them. sp/., funnel of sperm-duct. 



d., duct of s^permatheca. sp.gl., spermiducal gland, 



d.v., dorsal blood-vessel. . sp.s., sperm-sac 



g., gland-cells in intestinal epi- 

 thelium. 

 gl., gland surrounding spermathecal 



pore. 

 lit., lateral heart. 

 int., intestine. 



spth., spermatheca. 

 t., testis. 

 ty., typhlosole. ty.v., typhlosolar 

 blood-vessel. 

 v., ventral chaetic. 

 V.V., ventral blood-vessel. 



EXPLANATION OF THE PLATES. 

 Plate XXIV. 

 Taupodrilus simple.v, p. 209. 

 Fiff 1 View of the ventral surface of the genital region of the body, showing 

 extent of clitellum, the position of the genital pores, and the protruded 

 copulatory chaeta. . j. a • i 



2 Side view of five pregenital segments as seen m a transparent, stanied 

 specimen. (X 120.) To show certain features of the vascular system. 



3. A bundle of dorsal chffitse. .,, . ^ ^■ . a 4. ^ ^ 



4. One of the ctenates from a dorsal bundle, with intermediate denuicles. 



(X 700 ) 

 4 a. The tip of another dorsal chaita, showing the membrane joining the two 

 * prongs. (X 700.) 



5. A chajta from a ventral bundle. (X 700.) /^«aa\ 



6. The tip of another ventral chsta with intermediate denticle. (.X iw.) 

 7 One of the bunch of copulatory chffita3. (X 700.) 



8. Side view of the genital organs as seen in a bisected specimen ; somewhat 

 diagrammatised, x, point of entrance of sperm-duct into atrium. 



9 A pOTtion of the wall of the atrium from a longitudinal section oi the same. 

 (X 500. The detaUs studied with a tV homogeneous immersion ot Leitz.) 

 The wall is seen to consist of a single layer of much vacuolated cells, the 

 boundaries of which are distinctly seen in the lower half of the fagure, 

 where the cells were cut verticaUy. The round nuclei near the outside 

 belong to the gland-cells ; the oval nuclei towards the lumen seem to belong 

 to compressed columnar cells, whose limits are not distinguishable. 



The sperm-duct is cut through twice as it winds up outside the wall, 

 and again (at d') where it is perforating the wall. 



Plate XXV. 



Limnodrilus vejdovshyanus, p. 213. 



Fig. 10. Tip of a dorsal chajta. (X 700.) 

 11. Tip of a ventral chaita. (X 700.) 



12 A side view of two segments of the body to illustrate the peculiar arrange- 

 ment of the " heart " in segment viii., where it closely embraces the gat 

 around the line of union of oesophagus with intestine. Ihe anterior 

 portion of the dorsal vessel is in outline, as is also the commissural vessel 

 of segment vii. The posterior portion of the dorsal vessel and the sapra- 

 intestinal vessel are in black, as are also the intestinal vessels. 



13. An obliquely transverse section of the gut in segment viii. ihe lateral 



heart lies in the furrow between the oesophagus and intestine. 



14. The penial tube. (Camera, X 120.) 



