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10. 
Description of some Fossils from a Croydon Garden. 
EXPLANATION OF PLATE II. 
Porosphera globularis, Phill., sp. A small specimen, pre- 
served in flint, showing the spicular structure of the 
exterior. x 50diam. Upper Chalk; near Sidcup, Kent. 
Collection of Mr, H. Muller. 
Ditto; portion of the outer surface, showing the arrangement 
of the skeletal spicules bounding the apertures of the 
radial canals. x 40diam. Zone of Belemnitella mucro- 
nata; Ballard Cliff, Dorset coast. Collection of Dr. 
Rowe. 
Ditto; three-rayed spicules of the dermallayer. x 100 diam. 
Zone of Actinocamax quadratus; Scratchell’s Bay, 
Isle of Wight. Collection of G. J. Hinde. 
Porosphera nuciformis, v. Hag.,sp. Portion of the surface, 
showing the skeletal spicules and the radial canal aper- 
tures. x 40diam. Zone of A. guadratus; Cliff, east, 
of Brighton. 
Porosphera pileolus. A four-rayed mesh spicule, the apical 
ray armed with lateral prickles. From a microscopic 
section near the margin of the specimen. x 200 diam. 
Zone of Micraster cor-anguinum; South Croydon. 
Collection of G. J. Hinde. 
P. globularis. A portion of the skeletal mesh, showing its 
structure of four-rayed spicules, the basal rays of which 
are now fused together. x 100 diam. Zone of M. cor- 
anguinum; South Croydon. Collection of G. J. Hinde. 
Ditto; a fragment of the dermal layer, showing three- and 
four-rayed spicules irregularly intermingled. x 50diam. 
Zone of B. mucronata; Ballard Cliff, Dorset coast. 
Collection of Dr. Rowe. 
Ditto; a small specimen preserved in chalk, showing blunted 
apical rays of spicules projecting from the surface. 
x 40 diam. Upper Chalk, Gravesend, Kent. 
Ditto; the skeletal mesh near the margin of a specimen pre- 
served in flint, showing the curved facial and the pro- 
jecting apical rays of four-rayed spicules. x 40 diam. 
Upper Chalk; Chatham. Jermyn Street Museum. 
Ditto; portion of the outer surface of the dermal layer, showing 
* rod-like spicules arranged concentrically round a central 
“i pore (?). x 50diam. Zone of Belemnitella mucronata ; 
Ballard Cliff, Dorset coast. Collection of Dr. Rowe. 
