SPKLERA. 



159 



Remarks. — This species is the type of the genus Sphaera. It is fairly common 

 in the Pema-bed of the Isle of Wight. A young example is figured by d'Orbigny. 



Type. — The type was obtained by Professor Sedgwick from the Pema-bed of 

 Sandown, but cannot now be found. 



Fig. 26.— Sphxra corrugata, Sow. Lower Greensand, near Hythe. Museum of Practical Geology, 



No. 19716. Dorsal view, x a. 



Distribution. — Lower Greensand (Pema-bed and Crackers) of Atherfield ; also 

 recorded by Fitton from Beds viii and xiv. Hythe Beds of Hythe and Maidstone. 

 Recorded by Topley from the Atherfield Beds of Peasmarsh and Shalford; the 

 Hythe Beds of Lympe ; and the Sandgate Beds of Sandgate. 1 



Spilera, sp. Plate XXV, fig. 3. 



A small specimen from the Chalk Marl of Chard appears to belong to a distinct 

 species. It is much smaller than S. corrugata, also relatively longer, more oval in 

 outline, and less inflated. The escutcheon is not defined, the lunule is small or 

 absent, and the antero-dorsal margins are thick and prominent. The concentric 

 ridges resemble those of 8. corrugata, but the radial ribs are more distinct. Length 

 16*5 mm. ; height 14 mm.; thickness 12 # 5 mm. 



1 The type of Corbis ? fibrosa, Forbes, from Peasmarsh, is in the Museum of the Geological 

 Society (R2154), but is too imperfect for determination. Forbes, 'Quart. Journ. G-eol. Soc.,' vol. i 

 (1845), p. 239. 



