54 



COELENTERATA— PORIFERA 



PHYLUM II 



(ostia and postica). Skeleton composed of smooth-rayed tetraclons, the digitate 

 extremities of which are inflated into balls. Dermal spicules in the form of 

 anchors and rods. Upper Cretaceous. 



Phymatdla Zittel (Fig. 50). Upper Cretaceous. 



Polymaraphinina, Sollasella, Pseudoplocoscyphia and Craterella Schramm en. 

 Upper Cretaceous. 



Fig. 53. 



Skeletal element of Jerea 

 qvensteiUi, Zittel, showing 

 brandling extremities of 

 rays. Qnadratenkreide; Lin- 

 den, near Hanover. ■''Vi. 



Fig. 54. 



Zittel. 



Plintlwsella squamosa 

 Skeleton mai;nified 80 diameters. 

 Senonian ; Ahlten, Hanover. 



Fig. [>2. 



Jerea pyriformis Lamx. 

 Greensand ; Kelheim, Ba- 

 varia, i/o natural size. 



Siphonia Park. 

 (Fig. 51). Fig-, pear- 

 or apple-shaped, with 

 a long or short ped- 

 uncle. Body with 

 deep cloaca, into 

 which arched canals 

 running parallel with 

 the periphery, to- 

 gether with numerous 

 fine radial canals, con- 

 duct. Skeleton com- 

 posed of smooth-rayed, branching dichotriders. Dermal spicules in the form 

 of monaxons and grapnels. Abundant in Middle and Upper Cretaceous. 



Hallirhoa Lamx. Like the preceding, but invariably short -stemmed. 

 Body pyriform and lobate, owing to a number of deep constrictions. 

 Cenomanian. 



Jerea Lamx. (Figs. 52, 53). Body pyriform, flask-shaped or cylindrical, 

 with truncate or depressed summit, in which a number of tube-like canals, 

 vertical in the central portion but arched in the peripheral, terminate. Cross- 

 ing the latter are finer radial canals. Skeleton composed of tetraclons and 

 dichotriders. Common in Middle and Upper Cretaceous. 



Bhaijadinia rimo.'^a Roemer. 

 natural size ; h, Skeleton, 40/j 

 Spicule of dermal layer, -I'V]- 



Pio. 55. 



Senonian ; Alilten, Hanover, a, Sponge, 

 c, Lobate disk from dennal layer, -lO/i ; 



