[i43] 
XI. J Letter from Mr. Emanuel da Cofta 
F. R. S. to the Prehdent, concerning two 
beautiful Echinites. 
SIR, 
Read May u. X HAVE the Honour of laying before 
X, you (in order to communicate to the 
Royal Society , if you think it worthy) the Defc ip- 
tion of two Echinites , or Stones moulded in folTil 
Echini Shells, hitherto undefcnbed, as far as I know. 
Thefe Echinites ate undoubtedly moulded in 
Shells, of a Genus of which weatprefent find fome 
Species now living in the Seas ; moltly in the Wejl 
Indies . The Echinometra of Arifiotle , Alarovand , 
and of Dr. Grew (a), is of this Genus. Dr. Breynius 
(h) calls the whole Genus Echinanthus ; and Mr. 
Klein {c) Scutum. Woodward (d) in his Diftri- 
bution of foil'll Echini calls them the Fentaphyl- 
loides , from the Rays on the upper Part forming a. 
beautiful cinquefoil Figure ; but wrongly fixes their 
Charaderiftics in having only one Aperture, and that 
at the Balls; in which he not only contradids Na- 
ture, but alfo the very Specimens he quotes in his 
own Coiledion, which have all two Foramens or A- 
pcrtures, and are elegantly figured fo by Agojtino Scilla 
\e) who was thePerfon that fent them to the Dodor; 
and 
(a) Mufeum Reg. Sac. p. 139. (b) Schediafma de Echinis, 
p. 60. (r) Nat. Difp. Echinodermatutn, p. 20, Tab. 17. 
A , etTAB. 18, B. ( d ) Cade of foreign extraneous Foffils,/>. 16. 
(e) La vana Speculazione difmgannata dal fenfo , Tab. 9, 10, 
and 11. 
