148 INVERTEBRATA. 



or projecting as prominent craters or tubes (var. tubifera, Kpng.). 

 'JLVo specimens in the Woodwardian Museum have a well-marked, 

 expanded, flattened, and everted margin, and these specimens 

 further agree in being of stouter build than is usual in the ordinary 

 forms thus agreeing with the type of E. marginata. 



The vermiculate structure of the sponge is well seen over the 

 outer surface, but on the oscular face the tissue is denser, forming 

 an ' epitheca ' which is however less developed than in the Farring- 

 don sponges. 



Localities. Upware, Brickhill, Farringdon. 



N. Europe. Schb'ppenstedt (Hils conglom.), Dresden 

 (Planer) ? 



Europe. Ardennes, Arzier (Vaud). 



ELASMOSTOMA PEZISA, Goldfuss. 



Manon pezisa, Goldfuss, Petr. Germ., L, pi. I., figs. 7, 8 (not the 

 other figures). 



Elasmostoma consobrinum, d'Orb., Geinitz, and others. 

 Localities. Brickhill, Upware, Farringdoa. 



CORYNELLA NODOSA, sp. HOV, 



(Plate viii., fig. 4.) 



Description. Sponges more or less pyramidal, rarely cylin- 

 drical ; attached by a broad base ; sessile, or mounted upon a short 

 neck. 



Walls very thick, composed of an uniform, coarse vermiculate 

 tissue, leaving only a narrow cylindrical central cloaca. 



The system of canals opening into the central cloaca is but 

 imperfectly developed. 



Osculum terminal, central. 



A simple smooth area forms the terminal cone around the 

 osculum, but below this the surface is raised into prominent, coarse 

 knobs and foldings. 



Locality. Brickhill. 



