Plate X. 



Figs. 1-1)5. AuJosaccKS initsulmrU I.j. P. 117. 



Fii;'. I. The type-specimen in the Sei. Coll. ]\Tnseuni (No. 427), attached 



to Isis. ^ nat. size. (Figs, ^-l;") were all taken from this 



specimen). 

 Figs. 2, 3. Macrodiscohexasters. 300 x . 

 Figs. 4-7. Oxjhexasters. 300 x . 

 Fig. 8. Microdiscohexaster. 300 x . 

 Fig. 9. Dermalia. 300 x. 

 Fig. 10. Gastralia. 300 x. 

 Fig. 11. Showing the si^iculation of the wall. Almve, a eomilns with a 



tuft of prostalia. 20 x . 

 Fig. 12. A small part of a section through the liody-wall, stained with 



hfematoxylin. Above, two dermalia and the dermal membrane. 



The latter connected with the choanosome by a pillar consisting 



of spicules and a dense cobweb of trabeculfe. Below, parts of 



two flagellated chambers. 100 x . 

 Fig. 13. A gastralia with the free ray directed downwards, and the 



trabecular cobweb in connection with it. 100 x . 

 Fig. 14. Chamber wall (membrana reticularis) in optical section. 1000 x . 

 Fig. 1."). Same in surface-view. Below, a. group of strongly stained 



archreocytes. 1000 x . 



Figs, lG-23. Acanfhnscns alairi It. P. 158. 



Fig. iC). The type-specimen now belonging to the lîritish Museum. .] nat. 



size. 

 Fig. 17. Dermalia. 300 x. 

 Fig. 18. Gastralia. 300 x. 



Fig. 19. Discoctaster. 300 x. (The terminals are drawu a little too jliiek.) 

 Figs. 20, 21. The .two varieties of oxyhexaster. 300 x. 

 Fig. 22. Microdiscohexaster. 300 x . 

 Fig. 23. Skeletal ])arts of the ectosome : dermal lacework and hy[iodermal 



strands. 50 x . 



