240 M. K. A. Zittel un Fossil Lithitstidce. 



c. Sponge-body massive, cylindrical ; vertex convex, trun- 

 cate, or depressed. In the interior vertical tubes, either scat- 

 tered or grouped in bundles. Radial canals simple, radiating 

 from the centre towards the periphery. 



Sfichophi/ma, Pom. (Cretaceous). Vertex convex, with scattered warty 

 oscula, connected with vertical tubes. 



Jereica, Zitt. (Cretaceous). Vertex truncate or depressed, with a bundle 

 of vertical tubes iu the middle. 



Pomelia, Zitt. (Miocene, Recent). Clavate ; vertex convex, with nume- 

 rous fine vertical tubes opening into a small depression ; at the 

 sides also isolated pits furnished with tubes. Surface finely porous. 



d. Sponge-body cylindrical, trochiform, or globular, thick- 

 walled, with a simple central cavity. Oblique, capillary, per- 

 forating, and sometimes also coarser radial canals opening into 

 the stomachal cavity. 



Ccplocoi-i/pha, Zitt. (Cretaceous). Globular or trochiform. Stomachal 

 cavity shallow ; only fine radial canals. 



Scytalia, Zitt. (Cretaceous). Cylindrical. Stomachal cavity reaching to 

 the base ; besides the fine radial canals there are coarser ones 

 opening into the stomachal cavity. 



Pachininn, Zitt. (Cretaceous). Cylindrical. Stomachal cavity wide, 

 deep ; skeletal elements knobby, very large ; surface- corpuscles small, 

 fine, bi'anched. 



Stachi/sjwm/ia, Zitt. (Cretaceous). Cylindrical. Stomachal cavity sim- 

 ple, tubular ; surface A\ith conical tubercles. 



Family 2. Megamorina. 



Skeletal elements large, elongated, smooth, curved, irre- 

 gularly branched, or only forked at the ends, Avith a simple 

 axial canal, loosely interlocked with each other (PL VIII. 

 figs. 3 & 4). Among them sometimes smaller skeletal cor- 

 puscles of Hhizomorine type. Surface-spicules uniaxial or 

 forked anchors. 



Megalithista, Zitt. (Jura). Cylindrical or basin-shaped, with simple 

 central cavity. In the surface-layer numerous bacillar spicules and 

 a few forked anchors. 



Dori/denna, Zitt. (Cretaceous). Cylindrical or branched, with a bundle 

 of vertical tubes in the centre. Surface meshed ; in the meshes there 

 are tufts of short-toothed forked anchors with vei-y long shafts 

 turned inwards. 



Lyidium, Schm. (Recent). Basin-shaped ; on both surfaces with ostia 

 of coarse simple canals. Skeletal elements branched, smooth, with 

 thickened ends. Surface-spicules uniaxial. 



Carterelki, Zitt. (Cretaceous). Cylindrical, much elongated, with tra- 

 versing vertical tubes. Skeletal elements very long, very sparsely 

 branched. 



Jsorhaphinin, Zitt. (Cretaceous). Cylindrical, with a wide central cavity. 

 Skeletal elements spiculifonn, only slightly forked or thickened at 

 the ends. 



