PLATE III. 



Fig. 1. Portion of the skeleton of Spongelia pallescens, 0. Schmidt; natural size. 



Fig. 2. Skeleton of Spongelia liomda, Selenka ; natural size. 



Fig. 3. Fragment (?) of a specimen of Psammopemma densiim, Marshall ; natural size. 



Fig. 4. Portion of a section through its body showing the form and disposition of tlie 

 flagellated chambers ; x 300. 



Fig. 5. A colonial .specimen of Psammoclcnia vosmaeri, n. sp.; natural size. 



Fig. 6. Portion of a section through one of its individuals ; x 300. 



Fig. 7. Portion of the skeleton of Psammoclema foliaceum, n. sp.; natural size. 



Fig. 8. The same of Psammoclema ramosnm, Marshall ; natural size. 



