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Matter (tho* unlike every thing of that kind yet de- 
fcribed), or to fome other Caufe, which he don’t 
pretend to know *f*- 
The Configuration feems nevertheiefs in fome 
meafure to correfpond with the Nature of the Shell 
wherein it was formed : As to the Number of the - 
Rows of Cells, they being ranged by Fives, as 
the TapilUy Indentings , Lines , or other Marks on 
the 'recent Shells of Echini conftantly are 5 thefe 
Rows are twenty in Number 5 viz., five double Ranks 
of large and extremely regular Cells, as at a a, &c. 
between which lie five other double Rows of fmaller 
and lefs difiind Cellulre , {hewn at bb , &c. Thefe 
Cells, which are hexagonal, and whereof thofe in 
every Row lie alternately to thofe of the next (by 
which means they fill up the whole Space)* decrease 
in their Size gradually, as they approach nearer to 
the Top 5 all the Rows at laft almoft concentring at 
the Apex-> leaving only a fmall Space or Vacuity, 
where in the Shells themfelves of this kind of 
Echinus there is an Aperture. The fmooth Part at 
A is formed of a pebbly Stone, bearing the fame 
Marks as are ufually found in the Impreffion of 
thefe Echinita dug up in Gravel Pits j which proves, 
that this muft have receiv’d its general Figure from 
one of thofe Shells, whatever has been the Caufe of 
this remarkable Configuration of the cryftallinePart. 
This curious Echinite was found in a Marl-Pit at 
Baborough , about three Miles W eft of the City of 
Norwich , and prefented to Mr. Baker by Mr. JVm.* 
Arderon , F. R. S. 
t Perhaps to fome Cells or Membranes belonging to the Body of 
the Echinus . C, M, 
