BUB-CLASS I 



1 1 V I mOZOA TUBULARIAE 



111 



extend continuously through ;i number .f lamellae. Both lamellae and pillars^ 

 consist .f i.iii.utcly tabulated tissue, the tubules of which are radial in arrange- 

 ,,,,-nt. Centre fluently occupied by .-i foivign body. Cambridge Greensand 

 (Cenomanian). 



Tin- genera Parteria and h,ftn*i" \v'iv originally described as agglutinate. 

 Foraminifera : but they are manifestly very closely allied to Ellipsadinia and 

 Sphaeractinia, 



Powphacra, Steimn. (Fig. 196). Globular masses of the size of peas or 

 ha/el nuts, t're<|uently growing around some foreign body, and composed of 

 anastomosing calcareous fibres which are penetrated by 

 numerous radial tubules : the latter open on the surface in the 

 form of lar^e pores, around which radial or stellate furrows 

 (,i*tmrl,i\i>i } are sometimes grouped. Upper Cretaceous. 



FIG. 195. 



l.i'ftusiii Pentad, Brady. Eocene; Persia. A, Specimen cut open to show general 

 structure, natural size (after Brady). li, Section showing two lamellae and inter- 

 liiininar lillinj:, greatly enlarged. 



FIG. 196. 



Porosphaera gldbu- 

 lrix, Phill. sp. Upper 

 Cretaceous ; Riigen. 

 .4, Skeleton, natural 

 size ; I, Cavity origin- 

 ally occupied by 

 foreign body. B, Trans- 

 verse section showing 

 radial tubes of gastro- 

 pores, '-/! (after Stein- 

 inann). 



Stolic.ihiri<i, Duncan. Trias ; Karakoram and Balkan Mountains. 



Hdernetridium, Reuss. (Syringosphaeria, Duncan). Spheroidal, nodular 

 bodies of considerable size, composed of slender, anastomosing, and more or 

 less distinctly radial calcareous fibres. Skeleton comparatively dense, but 

 perforated by two series of zooidal tubes appearing superficially as pores. The 

 apertures of the larger tubes are round, those of the smaller stellate, and are 

 surrounded by radial furrows. Alpine Trias. 



Appendix to the Hydrocorallinae and Tubulariae. 

 Stromatoporoidea. Nicholson and Murie. }( 



Closely allied to the HydrocoralUnae and Hydractinia are the extinct Stromato- 

 /><ii-ii/</('<i, \vhich combine in many respects the characters pertaining to both of 

 the above-named groups, but whose" exact position in the zoological system 

 n 'mains as yet uncertain. During the Palaeozoic era, to which they are con- 

 fined, the Stromatoporoids were important geological agents, whole beds of 

 limestone being often essentially constituted of their remains. In the Mesozoic 

 era they are replaced by very closely allied forms of HydractinM, which in all 

 probability represent their immediate descendants. 



The Stromatoporoids secrete hemispherical, globular, nodular, or horizontally 

 expanded skeletons, which are sometimes encrusting, sometimes attached by a 

 short basal peduncle, and are covered on the under side with concentrically 



