M. K. A. Zittel on Fossil Lithistidce. 387 



irregularly branched corpuscles, covered with verruciform 

 or spiny processes. Sometimes a part of the surface has an 

 apparently smooth covering-layer, formed of young, densely 

 interwoven skeletal corpuscles. 



The genus differs from Scytalia by its narrower and shal- 

 lower central cavity, its stouter gnarled corpuscles, and the 

 absence of large radial canals. No isolated spicules ob- 

 served. 



a. Simple forms : — 



1. Siphonoccelia nidulifera^ Rom. Spong. xi. 3. Senonian. 

 "^2. Eudea crassa, Rom. ib. x. 4. Senonian. 



3. Coelocorypha suhglohosa, Zitt. Senonian. 

 Spumispongia punctata p. p., Quenat. Petr. cxxxiv. 9, 13-15. 



4. Choitetes cretaceus, Trautsch. Bull. Mosc. 1877, vi. 5. 

 Senonian. 



5. 8ci/j)hia acuta^ Rom. Spong. ii. 4. Senonian, Sutmer- 

 berg. 



h. Compound forms : — 



6. Polycoelia familiaris, Rom. Spong. xi. 10. Senonian, 

 Sutmerberg. 



*7. Siphonia soctah's, Rom. Kr. ii. 5. Senonian, Sutmer- 

 berg. 



SCYTALIA, Zitt. 



Scyphia p. p., Siphonoccelia p. p., Jerea p. p., Eudea p. p., auct. 



Tuhidosponc/ia p. p., Court. 



? Cladocalpia, Calpia p. p., Pom. 



Sponge elongate, cylindrical, rarely clavate, simple or 

 branched, with a round, tubular central cavity, usually reach- 

 ing nearly to the base, into which open numerous radial 

 canals, becoming thinner outwards, and, frequently branching, 

 form pore-like ostia at the surface. From the lower extremity 

 of the central cavity perpendicular canals run into the narrow 

 base. Skeleton of curved corpuscles, with pointed processes 

 and somewhat branched ends ; among these are sometimes 

 scattered bacillar spicules and anchors with three and six 

 prongs. 



The forms placed here constitute a genus agreeing in ex- 

 ternal form with various siliceous and calcareous sponges of 

 quite different microstructure. Fromentel gave the name of 

 Siphonocoelia to all simple cylindrical fossil sponges with a 

 round central tube ; and this name has been generally accepted. 

 But the two species cited by him in the ' Introduction "k I'etude 

 des Eponges fossiles ' (^S*. elegans, Miinst., and 8. com2)ressay 

 From.) do not belong to the Lithistid^, any more than the 



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