The Hijlory of ANIMALS, 
*55 
Oftrea fubovata teriitior finuata . 
The thirty oval , finuated Oftrea. 
Xfye Xtee^opfter. 
This has been by many fuppofed to be the fame with the common oyfter, only dif¬ 
fering in it’s manner of growing ; but later obfervations have fhewn, that in places 
where it has the fame accidents attending it’s formation, as the common oyfter, it ftill 
preferves it’s diftindt form : it is about two inches long, and an inch and a half in dia¬ 
meter at the larger end : the hinge is placed at the fmaller extremity, which terminates 
obtufely, and from thence it gradually becomes larger to the oppofite end, where it is 
rounded and finuated at the edge: the whole furface of the fhell is deeply furrowed in 
a longitudinal direction, and is fomewhat rough, though not nearly fo much fo as that 
of the common oyfter: the colour is brown, with a faint admixture of reddifh on the 
outfide, and a pearly white within. When this fpecies is produced in the neigh¬ 
bourhood of robuft fea-plants, or other fmall and rounded bodies under water, it ad¬ 
heres to them, and there will grow, from the feveral parts of the fhell where it touches 
them, a kind of clavicles or clafpers, which feize upon, or meet round the thing, hold¬ 
ing the fhell faft to it. 
It is very frequent in the Weft Indies, where it abounds on their mangrove-trees 
covered by the tides, and has thence obtained the ftrange name of the Tree-oyfter. To 
this has been owing the report of oyfters growing on trees in that part of the world. 
Oftrea anguftior cafite tranfverfo. fcatnntM* ntrtW 
The narrow Oyfter , with a tranfuerfe head . 
This is by far the moft lingular of all the Oyfter-kind, and is indeed one of the 
moft extraordinary fhells in the world : it’s fhape is that of a hammer, or rather a 
pickax, with a very fhort handle, and a long head: the body of the fhell, which 
ftands in the place of the handle of the inilrument from which it is named, is about 
four inches long, and three quarters of an inch in diameter : what is called the head, 
and anfwers to the head of the pickax, is five or fix inches long, and, except where 
it joins to the body, is fcarce any where more than half an inch in diameter ; it ftands 
tranfverfely or croffwife to the body, and is irregularly formed, uneven at the edges, 
and terminates in a narrow but obtufe point at each end : the hinge is at the lower 
end of the body ; the valves open all the way from each end to this part, and, though 
of this ftrange figure, they fhut in a remarkably clofe and elegant manner : the edges 
of the body and head have often great irregularities and protuberances on their furface, 
and at their edges ; and are deeply furrowed and plated all over, the lines running in 
different and very irregular diredions: the colour is a deep brown, with a tinge of a 
violet purple on the outfide, and a pearly white, with fome faint tinge of purplifh 
within. 
It is a native of the Eaft Indies, and is a very rare fhell; when entire, which it 
very rarely is, it fells at a great price : fix guineas were, laft winter, given at an au&ion 
for an imperfect one. 
Oftrea horrida fpinis ereEUs et aduncis . 
The Oftrea , with numerous , ereEt> and crooked fpines 
%\yt great, 
• pn’cftlp £>pfter. 
This is a large and very elegant fpecies: it is of a figure approaching to oval, four 
inches long, and at the larger extremity near three in diameter ; at the fmaller, where 
the hinge is, it is about an inch and a half: both fhells are gibbofe and hollowed, but the 
under one moft fo : the whole furface of each is furrowed longitudinally, but fome¬ 
what irregularly, and is covered with a vaft number of fpines; they are robuft, fharp- 
pointed, and of various lengths, from half an inch to a tenth of an inch ; they ftand 
clofe and crowding upon one another, and fome of them are ftraight, others crooked : 
the colour of the outfide of the fhell is a dirty red, on the infide it is white and 
It is a native of the coafts of Africa, and we have it alfo in fome other places* 
Oftrea 
