M. K. A. Zittel on Fossil Calcispongia. 131 



Skeletal fibres coarse, apparently formed principally of 

 uniaxial, frequently curved bacillar spicules and scattered tri- 

 radiates. 



All the species occur in the Cretaceous. 



1. Tragos acutimargo, Rom. Nordd. Ool. Taf. xvii. fig. 26 ; 

 Spongit. Taf. i. fig. 21. 



Elasmostoma frondesccns, From. Tntrod. pi. iii. fig. G. 



2. Elasmostoma neocomiense, Loriol, Descr. anim. invert. 

 foss. Ne*oc. du Mont- Sale ve, pi. xxii. figs. 1, 2. 



3. ChenendroscypMa crassa, From. Cat. Rais. pi. iv. fig. 2. 



4. Porostoma porosa, From. ib. pi. iii. fig. 3. 



5. ChenendroscypMa mamillata, From. ib. pi. iii. fig. 4. 

 ? 6. Elasmostoma cupula, Rom. Spongit. Taf. i. fig. 22. 



7. Ocidospongia polymorplia, Rom. ib. Taf. i. fig. 16. 



8. Manon macropora, Sharpe, Q. J. G. S. x. pi. v. figs. 3, 4. 



9. Cupulospongia Normanniana, D'Orb. Prodr. ii. p. 188. 

 Manon peziza, Mich. Ic. pi. xxxvi. fig. 5. 



10. Manon peziza p. p., Goldf. Taf. xxix. fig. 8. 



11. Cupulospongia consobrina, D'Orb. Prodr. ii. fig. 188. 

 Manon peziza p. p., Goldf. Taf. i. figs. 7 , 8. 



Manon steUatum, Goldf. Taf. i. fig. 9. 



12. Spongia Trig&ri, Mich. Ic. pi. liii. fig. 2. 



Diplostoma, Fromentel (non Rom.). 



Forospongia p. p., D'Orb. 



Like Elasmostoma, but both surfaces furnished with smooth 

 epidermis and shallow oscula. Cretaceous. 



1. Diplostoma neocomiensis, From. Introd. pi. iii. fig. 3. 



Pharetrospongia, Sollas. 



Manon p. p., Chenendopora p.p., auctt. 



Cupvlispongia p. p., D'Orb. 



Cupulochonia p. p., From. 



Cupulospongia, I'hlgctia, Trachgphlgctia, P Heterophlyctia, ? Iteteropcxia, 



Pom. 

 Pharetrospongia, Sollas. 



Sponge cup-, funnel-, or leaf-shaped ; in the last case the 

 thick-walled leaf always bent or folded. Upper surface 

 ( = inner surface) usually smooth, with very small oscula or 

 only simple pores. Outer surface rough, porous. Canal-sys- 

 tem deficient, or consisting of fine tubes, which penetrate from 

 both surfaces into the wall. Skeleton consisting of anasto- 

 mosing vermiform fibres, which are entirely composed of 

 simple bacillar spicules. 



As Mr. Sollas has so admirably described (Quart. Journ. 



