C r 44 ] 
and our latePrefident Sir Hans Slodne (f) has alfo figu- 
red and defcribed two Species of this Genus , whereof 
one Species is an Inhabitant of our Englijh Seas. 
I obfcrved aoove, that, to my Knowledge, no 
Au r hor has ever defcribed Echinites or Stones 
moulded in the foil! Echini of this Genus-, nor even 
have the toll'll Echini or Shells themlelves been ever 
exhibited by any Lithologift, except by the above- 
quo- cd A. Scilla, who fent them to Dr. IVoodward, 
and round them in Malta ; to which the Do&or in 
h s Catalogue recounts two other Specimens, whkh 
were dug up in Maryland ; fo rare are the Instances of 
the Foflils of this whole Genus ! 
The two Echinites here defcribed (as alfo <omc 
few other Specimens ot this fort, which I hear are 
in fome Cabinets in this Metropolis) were ail fou d 
in the midft of fome Rocks, which were blown up 
at Tort Mahon fome Years ago, and fiom whence 
they were all brought. 
The fi ft or largeft is in the Pofl'eflion of the Riuht 
Rev. Dr. Lavington , Lord Biftiop of Exeter .• it is 
compofed of a hard or ftony arenaceous grc> llh Sub- 
ftancc, and is of an Efcutcheon or Heart- like Shape : 
It meafures about 14! Inches in Circumference, or 
quite round the Limb or Ed re, about two Inches 
high from the Elat or Balls to he Tip of the AptX , 
five Inches in Length at the Ba is, and 4-5- m Breadth. 
On the upper Part it rifts nc r y gradually from the 
Edge quite to the Ap x. A central Point, with a 
flight declining Space, tops the LidApex 5 from which 
Space 
(/) Nat. Hi/f. of Jamaica, Vcl. 2. Tab. 242, Fig. 3. ct feq. 
