ORDER III 



SILICISPONGIAE LITHIST IDA 



40 



Siphonia, Park. (Fig. 56). Fig-, pear-, or apple-shaped, with long or short 

 p.-dunele. IJody with deep cloaca, into which arched canals running parallel 

 with the periphery, together with numerous fine radial canals, conduct. 

 Skel.-tMi. composed o! smooth-rayed, branching dichotriders. Dermal spicules 



Fie. 58. 



Skeletal element of Jerea 

 Quenstedti, Zitt., showing 

 branching extremities of 

 rays. Quadratenkreide ; 

 Linden, near Hanover, *Yi. 



l-'i<;. 59. 

 I'liiitliaxi'Uii siiimniiiMt, Zitt. 



Skeleton magnified SO diamet.-ix. 

 Senonian ; Ahlten, Hanover. 



iiiu 



i i>!ir!f<innix, Lamx. 

 Greensand; Kelheim, 

 Mavaria. i/o natural size. 



in the form of mon- 

 axons and grapnels. 

 Abundant in Middle 

 and Upper Cretaceous. 



Ilnllirhoa, Lamx. 

 Like the preceding, but 

 invariably short -stem- 

 med. Body pyriform 

 and lobate, owing to a 

 numl)er of deep con- 

 strictions. Cenomanian. 



Jcrea, Lamx. (Fig. 

 57). Body pyriform, 

 flask-shaped or cylindrical, with truncate or depressed summit, in which a 

 iiinnlxT of tube-like canals, vertical in the central portion but arched in the 

 peripheral, terminate. Crossing the latter are finer radial canals. Skeleton 

 minpiised of tetraclons and dichotriders. Common in Middle and Upper 

 Cretaceous. 



J'oli/jerea, From., Astrocladia, Thecosiphonia, Calymmatina, Zitt., Turonia, Mich., 

 Plintlwsella, Zitt. (Fig. 59). Cretaceous. Discodermia, Boc., filiacodiscuki, Zitt., 

 etc. Cretaceous and Tertiary. 



Rhagadiwa, Zittel (Fig. 60). Ear-, plate-, or bowl-shaped, short- stemmed 

 Both surfaces traversed by irregular branching furro\vs, in which the canal- 

 icular ostia are situated. Skeletal elements four-rayed, sometimes uniformly 

 VOL. i E 



FIG 00. 



niifni. Ituriii. s]i. Sciioiiian ; Aliltfii, Hanover, f, S 

 - '.-; natural si/<> ; //, Skeleton, -o/j ; c> Lobiite disk from dermal layer, *' , 

 </, Spicule of dermal layer, 40/j. 



