C *98 J 
This Jhell is extremely thick, ftrong, 
opake and heavy ; of a fubtriangular 
fhape j rather deprefied, for the valves. 
are but moderately deep. The moft ge- 
neral fîze is that of a common plumb, or 
about one and a quarter inch long, and one 
and three quarters of an inch m breadth. 
Outfide, generally without any glofs, 
but of a rough appearance , of various 
colours, moftly whitifli, or pale yellowifli- 
brown j with fe-veral- concentric tranfverfe 
girdles or zones, blackifh, flate-colour’d, 
brown, &c. Thefe girdles are thick, broad, 
and ftrongly marked, in the live Jhells-, 
but in the dead Jhells [are very raifed and 
prominent, like ribs, the furfaee between 
them being often greatly eroded or worn 
down. The margins are plain -, the beaks 
pointed and central,. 
Infide, fmooth, but without any gloffi- 
nefs j whitifh, brown, or livid, &c. moft 
generally, paler than the -outfide colours. 
This fpecies is found in plenty on many 
of our Ihores, as Kent, Dorjetjhire, Kan- 
caJhire,TorkJhire, Northumberland, 
Cette coquille eft extrêmement epaifle, 
forte, opaque & pefante -, d’une forme 
quafi triangulaire 1 plutôt comprimée, 
car les valves ne font que modérément 
profondes. La grandeur la plus generale elr 
celle d’une prune commune, ou environ 
un pouce & un quart en longueur,. & un 
pouce & trois quarts en largeur, 
Uëxterieur, généralement fans luftre, 
mais d’une apparence rude ; de diverfés 
couleurs, la plufpart blanchâtre, ou paie 
jaunâtre brun, à plufieurs bandes ou zones. 
concentriques & tranfverfales, noirâtres, 
couleur d’ârdoifé, brunes, &c. Ces bandes 
font epainfes, lai*ges3& fortement mar-quées, 
für les coquilles vivantes -, mais fur celles 
qui font mortes elles font très hauffées & 
faillantes, comme des cotes, la furface 
entre elles- étant fouvent très frottée ou 
ufée. Les bords font unis i les pointus 
& centrais.. 
Le dedans, lifte,, mais fans aucun luftre 5 
blanchâtre, brun, ou livide, &c. gene-- 
ralement plus foible en couleur, que l’ex- 
terieur. 
Cette ejpece fe trouve en abondance fur 
plufieurs de nos cotes, comme aux comtés 
de Kent, Dorjet, Lancajler, York, Northum- 
berland, &c, . 
XXXIV.. XXXÏVL 
X. SuBTRUNCATA. SuBTRUNCATEO-i, 
Yrigonella albejeens lavis, lateribus Jubtruncatîs, Subtruncata. 
This Jpcies, like thç laft,^ is thick. Cette ejpece, comxnt la derniere, , eft 
ftrong, heavy and opake, but about half epaifte,^ forte, pefante, & opaque, mais 
its fize 3. of a triangular Jhape, for the environ la moitié en grandeur ir d’une 
fîdes are much flatted,, or, almoft trun- forms triangulaire, car les cotés font 
■cated, très 
