340 M. K. A. Zittel on Fossil LitMstidce. 



densely packed, forming a covering-layer which appears 

 almost smooth to the naked eye. 



The species were referred by D'Orbigny to Verrucospongia ; 

 but as calcareous and siliceous sponges of various genera were 

 embraced under this name, it is desirable to drop it altogether, 

 especially as there is a genus Verrucocoelta among the Hexac- 

 tinellidge. 



All the known species are Cretaceous. 



1. Manon turbinatum^ Rom. Kr. i. 5. Senonian, Sut- 

 merberg. 



2. Sticliophyma serialise Pom. p. 188. 



Manon turbinatum, Reuss, Bohm. Kr. p. 78, xix. 1-6. Cenomanian. 



3. Manon sparsurrij Reuss, Bohm. Kr. p. 78, xviii. 12-20. 

 Cenomanian. 



4. Polyje7'ea vet-rucosa, Rom. Spong. xiii. 5. Cuvieri- 

 Planer, Salzgitter. 



The following imperfectly known genera may be best ar- 

 ranged near Stichophyma. 



Allomera, Pom. 



(Pal. d'Oran, p. 194.) 

 Sponge simple, oblique^ attached by a thick stalk which is 

 often very short, almost sessile, globular or elongated, trun- 

 cated at the vertex, where in young individuals isolated ver- 

 tical tubes, and in older ones a bundle of such tubes open. 

 One side, which is made the upper by the oblique position of 

 the sponge, is of perfectly dense structure ; the surfaces of the 

 other sides are covered with fine pores. These are developed 

 especially on the surface turned downwards. Vertex dense, 

 with fine furrows. Skeletal structure unknown. Miocene of 

 Oran. 



Pleuromera, Pom. 

 (lb. p. 199.) 

 Sponge simple, lamellar, sessile. Lower surface with pores; 

 upper surface dense, with a pit into which canals open. Margin 

 thick, with fine furrows. Miocene of Oran. 



Perimera, Pom. 

 (lb. p. 200). 

 Polystoma p. p., Court, (non Zeder). 



Sponge nodular, compound. The individuals with a round 

 aperture in the vertex, communicating with a tubular stoma- 

 chal cavity. Certain parts of the surface with pore-like aper- 

 tures. Skeleton ? Upper Chalk. 



