10. 
Fig. 14. 
11535 
16. 
ie 
18. 
19. 
20. 
ON THE STRUCTURE OF THE AMMOCHARIDE. 
Vertical longitudinal section through centre of cephalic lobe, showing 
the brain (.) and cephalic (prostomial) pore (¢.p.) with its trans- 
verse muscular fibres. Ammochares filiformis (Naples). x 100. 
. Transverse section of ventral end of ‘‘ Lippen-organ,” showing the tall 
to} ? o 5 
clear secreting-cells (%.c.) and the underlying folded structure (/.c.). 
Ammochares filifurmis (Naples). x 100. 
Horizontal section through the anal lobes and pores (a.p.) of Ammo- 
chares filiformis (Naples). A deep section, showing the internal 
radiate arrangement of cells lining the pores. x 100. 
. Horizontal section, showing glandular structure of cells and lumina of 
anal pores (@.p.). Ammochares filiformis (Naples), 2. x 100. 
Anterior or exposed end of tube, showing the clear elastic tip of inner 
sheath, and the imbricated arrangement of the external stony covering 
(s.c.). Owenia filiformis (English). 
- Posterior or buried membranous end of tube of Owenia filiformis 
(English), showing its telescopic construction and consequent 
external stepped appearance; also the strengthening of the wider 
part by external disc-like additions (d.). x 22. 
PuarEe 25. 
Figs. 14, 15 & 16.—Stages in the development of the larva of 
Owenia filiformis. 
The embryo 48 hours after discharge of ova. 
oa) 
29 (a 99 ” 
me) 
39 fa 99 ? 
Larva of Owenta. Lateral view 96 hours after discharge of ova 
= Mitraria. 
The same, viewed from beneath. 
A ripe spermatozoon of Owenia. 
Ammochares filiformis (Naples). Ventral view. x 2. (From a 
preserved specimen.) 
