60 



COELENTERATA SPOXGIAE 



CLASS I 



convoluted wall. Folds separated on outer surface by deeply incised furrows, 

 on inner surface by shallow furrows. Framework extremely regular. Root 

 and dermal layer absent. Upper Jurassic. 



Venfriculites, Mant. (Fig. 79). Bowl-, plate-, beaker-, funnel-shaped, or 

 cylindrical, with wide cloaca. Wall thin, convoluted ; folds separated on both 

 sides by closely crowded longitudinal furrows. Lattice-work of skeleton more 

 or less regular ; outer layer thickened ; roots present. Common in Middle 

 and Upper Cretaceous. 



Schizorhabdus, Rhiwpotcrion, Polyblastidium, Zitt. ; Sporadoscinia, Pomel ; Lepi- 

 dospongia, Roem., etc. Cretaceous. 



Family 5. Coeloptychidae. Zittel. 



Umbel- or mushroom-shaped, with stalk. Wall thin, deeply folded. Convolutions 

 radially arranged, becoming furcate toward periphery of umbel, and exposed on lower 



FIG. SO. 



Coe'optychium agaricoides, Goldf. Upper Cretaceous; Vordorf, near Braunschweig. .-', Top view. B, Pro- 

 file. C Under surface, 2/ 3 natural size. D, Skeleton, 61^ 



surface. Marginal and upper surface enveloped with porous dermal layer entirely 

 covering the folds. Ostia only on under side of umbel, situated on backs of the folds. 

 Framework very regular; intersection nodes octahedral, perforated; rays of hexactins 

 provided with slender, thorny processes. 



Coeloptychium, Goldf. (Fig. 80), occurring in the Upper Cretaceous of 

 Northern Germany, England, and Southern Russia, is the solitary genue. 



