M. K. A. Zittel on Fossil Galcispongue. 129 



Synopella, Zittel. 



Tremospongia p. p., Sparsispongia p. p., D'Orb. ; From. 

 Tremospongia, Orosphecion, Aplosphecion, Pom. 



Sponge composite, rarely simple, hemispherical or nodular. 

 Upper surface plain, convex, or warty, with irregularly scat- 

 tered oscula, which are formed by the separated openings of 

 two or more large excurrent canals. Besides these oscula, 

 the surface is furnished with small ostia of fine incurrent 

 tubules. Base, and frequently also the sides, coated with a 

 thick wrinkled dermal layer. Skeletal fibres coarse. 



This genus is difficult to define sharply from Stellispongia 

 and Sestrostometta, although the typical species bear a pecu- 

 liar stamp. If the oscula are radiated by radial canals, as 

 now and then occurs, the distinction from Stellispongia is 

 difficult ; if, on the other hand, the roundish heads project 

 more definitely from the mass, transitions towards Sestrosto- 

 mella are produced. To the present genus I refer only nodu- 

 lar forms in which the individuals are not sharply defined, 

 but amalgamated with each other. 



The species are distributed through the different horizons 

 of the Cretaceous formation. 



1. Lymnorea sphcerica, Mich. Ic. pi. lii. fig. 16. 



2. Tremospongia plana, From. Introd. pi. iv. fig. 10. 



3. Manon pulvinarium, Goldf. Tab. xxix. fig. 7. 



Oculospongia, Fromentel. 



Manon, Goldf. 



Oculispongia p. p., Tremospongia p. p., Rom. 



Oculospongia, Sphecidion, Pom. 



Sponge nodular or clavate, massive ; vertex with but 

 slightly scattered, circular oscula, from which tubular canals 

 penetrate into the skeletal mass. Outer surface with or with- 

 out a wrinkled dermal layer. Skeleton consisting of coarse 

 anastomosing fibres. 



This genus is distinguished from Synopella merely by its 

 simple circular oscula, which are not composed of several 

 apertures. Jurassic and Cretaceous. 



? 1. Spjongites sella and binoculatus, Quenst. Petr. cxxvi. 

 figs. 58, 59. 



2. Oculospongia neocomiensis, From. Introd. pi. ii. fig. 8. 



3. Tremospongia dilatata, Horn. Spongit. Taf. i. fig. 24. 

 ? 4. Limnorea mamillaris, Horn. Spongit. Taf, i. fig. 14. 



5. Oculospongia flabellata , From. Cat. Rais. pi. iii. fig. 4. 



6. Oculospongia irregularis, Loriol, Land. pi. v. fig. 18. 



