204 
EDAVIN S. (lOODRICII. 
Fig. 12. — Next section to that drawn in fig 10. 
Figs. 13 and 11. — Two consecutive sections through the ventral end 
of the anterior limb of a nephridial canal. Cam. L. jb oil-imni., oc. 3. 
PLATE 13. 
Figs. 15, 1(>, and 17. — Three consecutive sections, parallel to a gill- 
bar. through the extremity of a diverticulum of the nephridial canal. 
Cam. Z. 2 mm. ap. oil-imm., oc. 12. In figs 15 and 10 the solenocyte 
tubes are cut in the thickness of the wall of the canal. 
Fig. 18. — Section across the ends of two adjacent nephridial diver- 
ticula. The bases of solenocyte tubes are clearly seen embedded in the 
cytoplasmic wall. Cam. Z. 2 mm. ap, oil-imm., oc. 18. 
Fig. 19. — Longitudinal section cutting the surface of a nephridium. 
Cam. L. oil-imm., oc. 3. 
Fig. 20. — View of the portion of the next section corresponding to 
the left-hand region of fig. 19. 
Fig. 21.— Similar section of another nephridium. 
Fig. 22. — Diagram to illustrate the direction of the sections drawn in 
figs. 5, 9, 10, 13, 15, and 19. 
PLATE 14. 
Fig. 23. — Section across the toj) of one primary and two secondary 
gill-bars, showing the position of the solenocyte chambers (ch.), and of 
the blood-vessels. The position of the external pore at a lower level is 
indicated by a cross X. 
Fig. 24. —Transverse section of a larva, passing through the mouth, 
and oiiening of Hatschek's nephridium. Cam. Z. D., oc. 3. 
Fig. 25. — Transverse section farther forward passing just beyond the 
anterior end of Hatschek's nephridium, where the cavity in which it lies 
opens into the first myocade. 
Fig. 26. — More enlarged view of a portion of the next section, 
sliowing the solenocyte tubes in a cavity continuous with the first 
myocccle. 
Fig. 27. — Anterior end of an adult Amphioxus, ventral view. The 
buccal cavity has been opened up by cutting along the mid-ventral line 
H;itschek's nephridium is seen on the left side of the notochord. 
