106 



Fig. 8. Another branch, on which the terminal cseca only form small vesicular 

 enlargements. 



Fi(/. 9. An ovary of a very young specimen, viewed from the exterior side, strongly 

 magnified. 



lig. 10. The same viewed from the interior side. 



Fig. 11. A terminal ramification of an ovary drawn from a fresh living specimen. 

 Inside of the half-transparent ovarial cuticle, there appear numerous egg-cells in different 

 stages of development. 



Fig. 12-15. Egg-cells in different stages of development, with an evident germinal 

 vesicle. 



Fig 16. A fully developed egg, in which the germinal vesicle is not visible; the 

 yellowish red mass of yolk is surrounded by a thick pellucid chorion. 



Fig. 17. The basal part of an arm of a full grown male specimen, viewed from 

 above. The dorsal skin is, as in fig. 4, cut along the middle and extended on the sides, in 

 order to expose the strongly developed seminaries. 



Fig. 18. A seminary of a younger specimen, isolated, viewed from the interior side. 



Fig. 19. The same, seen from the exterior side, a, the genital aperture. 



Fig. 20. A branch of the same seminary, isolated. 



Fig. 21. The extremity of a branch of a fully developed seminary, drawn 'from a 

 fresh living specimen. 



Fig. 22. Some of the developing cells of the spermatozoa, strongly magnified. 

 . lig. 23. A fascicle of fully developed spermatozoa. 



Fig. 24. 3 spermatozoa isolated, very strongly magnified. 



Fig. 25. An arm of a fully developed female specimen, viewed from the lower side. 

 The skeleton of the arm, together with the parts in connexion, has been removed, in order 

 to shew the organs lying above it in the cavity of the arm in their natural position: 

 a a a, the radial cteca with their 2 branches; h b, the ovaries; c c, the 2 genital apertures 

 situated symmetrically. 



^X^ab. IV. 



Fig. 1. The skeleton of the disc (the oral ring) of a fully developed 10-armed spe- 

 cimen, seen from above, slightly magnified: a a, the radial spaces; I b, the interradial 

 spaces; c, oral spines. 



lig. 2. The same viewed from below. 



Fig. 3. The same viewed from the side. 



Fig. 4. A piece of the oral ring, more strongly magnified, seen from above. 



