126 M. K. A. Zittel on Fossil Cakispongia?. 



2. Cnemidium variabile, Miinst. ib. Taf. i. figs. 21-23. 

 Cnemidium turbinatum, Miinst. ib. Taf. i. fig. 19. 

 Cnemidium stellare, Klipst. Oest. Alp. Taf. xx. fig. 6. 

 Cnemidium concinnum, Klipst. ib. Taf. xx. fig. 7. 



3. Tragos hybridum, Miinst. Beitr. iv. Taf. i. fig. 16. 



b. From the Jura. 



1. Spongia stellata, Lamx. Exp. Me*th. pi. lxxxiv. fig. 13. 

 Spongia umbellata, Mich. Ic. pi. lviii. fig. 1. 



2. Enaidofungia corallina, From. Introcl. pi. iii. fig. 11. 



Enaulofungia globosa, From. ib. pi. iv. fig. 1. 



Cnemidium pi'siforme and rotula, Mich. Ic. pi. xxvi. figs. 6, 7. 



Asterospongia coraUina, Etal. Leth. Taf. lix. figs. 8, 9. 



3. Sjjongites glomeratus, Querist. Jura, Taf. lxxxiv. figs. 10, 



Didesmospongia Thurmanni, Etal. Leth. pi. lix. fig. 3. 



Stellispungict pertusa, aperta, lujbrida, and glomerata, Etal. Leth. 



pi. lix. figs. 4-7. 

 Cnemidium stellatum, Mich. Ic. pi. xxvi. fig. 8. 

 ? Asterospongia rugosa, Etal. Leth. pi. lix. fig. 10. 



4. Geriospongia mundus-stellatus, Etal. Leth. pi. lix. fig. 11. 

 Diasterofungia mundistellata, From. Coll. de Lern. pi. xii. fig. 13. 



5. Ceriospongia bernensis, Etal. Leth. pi. lix. fig. 12. 



6. Spongites semicinctus, Quenst. Petr. Taf. cxxv. figs. 2-9. 



c. From the Cretaceous. 



1. Stellispongia sequana, From. Cat. Rais. pi. iii. fig. 2. 



2. ? Stellispongia subghbosa, Rom. Spongit. Taf. i. fig. 20. 



Sesteostomella, Zittel. 



Tremospongia p.p., D'Orb. 

 Sparsispongia p. p., Tremospongia p. p., From. 

 Sparsispongia p. p., Diestosphecion p. p., Pom. 

 Spongites p. p., Nudispongia, Quenst. 

 Palaqjerea, Laube. 



Sponge simple, or more frequently compound, tufted or com- 

 posed of verruciform individuals standing on a common base. 

 Individuals distinctly separated, cylindrico-clavate or semi- 

 globular ; vertex with a shallow, sometimes radiate osculum, 

 into which a great number of round ostia of vertical tubular 

 efferent canals open. Surface porous, naked, or the base and 

 sometimes also a part of the sides clothed with a dermal 

 layer. 



The calcareous sponges belonging to this genus have 

 hitherto been described under the names of Sparsispoiiyia, 

 Tremospongia^ or Pglceojerea. Under the name of Sparsi- 



