M. K. A. Zittel on Fossil Lithistldce. 473 



3. Siphonia Gelnitzi, Zitt. Cenomanian. 

 Siphonia py)-iformis, Gein. Elbth. i. p. 38, Taf. 9, 10. fig. 4, 



4. Siphonia hovisfa, Gein. ib. x. 5, 6. Cenomanian. 



5. Siphonia Jicus, Goldf. Ixv. 14. Senonian. 



6. Choanites Kcenigi^ Mant. Geol. Suss. xvi. 19-21. Up- 

 per Chalk. 



7. Siphonia incrassata, Goldf. xxx. 5. Senonian. 



8. Siphonia nuciformis^ Mich. Ic. xxxiii. 4. ? Cenoma- 

 nian. 



9. Siphonia multioculata^ Mich. ib. xxxiii. 6. Turonian. 



10. Siphonia arhuscida, Mich. ib. xxxiii. 2. Turonian. 



11. Siphonia ficoidea^ Mich. ib. xxix. 5. Cenomanian. 



12. Siphonia acaidis^ Mich. ib. xxxviii. 2. Cenomanian. 



13. Siphonia ornata, Rom. Spong. x. 9. Quadratus- 

 chalk. 



14. Siphonia MorrHsi. Mant. Med. ed. 2, p. 254. Upper 

 Chalk. 



15. Siphonia Fittoni, Mich. Ic. xxix. 6. Senonian. 



Also numerous, mostly ill-characterized, forms described by 

 Courtiller, e. g. S. decipiens^ oscidata, parasitica, sphoirica, 

 curta, cylindrica, intermedia, conica, rarioscidata, &c., many 

 probably identical with previously described species. 



B. Subgenus Hallirhoa, Lamx. 



1. Hallirhoa costata, Lamx. Mich. Ic. xxxi. 3. Ceno- 

 manian. 



2. Hallirhoa brevicostafa, Mich. ib. xxxi. Cenomanian. 



3. Hallirhoa Tessonis, Mich. ib. xxxiv. 1. Cenomanian. 

 Here also probably Scyphia alata and palmata, Court. 



JekeAj Lamx. 



(Expos. Meth. p. 79.) 



Siphonia p. p., Jerea p. p., auct. 



Manon p. p., Goldf. 



Rhysospongia, Jerea, Oupulina, Siphonia p. p., Coiu't. 



Poiypothecia p. p., Benett, Mich. 



Jerea p. p., Rhizospongia {Rhysospongia^, D'Orb. 



Jerea, Polyjerea p. p., Rhizospongia, Rhizostele, Rhizogonium, Pom, 



Sponge pyriform, globular, reversed flask-shaped, conical 

 or cylindrical, simple, rarely forming branched stocks, with a 

 short or long stalk, and more or less thickened, sometimes 

 dilated or branching base. Vertex truncate or with a depres- 

 sion, always with a number of round apertures, the orifices of a 

 bundle of vertical tubes which traverse the whole sponge 

 to its base, either perpendicularly or more or less parallel to 



