232 ECHI 
Flat on 150111 Tides; the avenues, refembling petals; 
mouth central, flat, toothed ; crown with four pores. 
61. Echinus “hit'oris, the two-holed Tea-urchin: the bale 
with live-grooves and ten flexuous radiate lines; near the 
vent two .oblong foramina. Above a little convex and 
pale yellowifh-afh, beneath ochraceous; Tometimes round- 
iill, (ometimes obtufely triangular; tlie margin Tometimes 
iinuous, (ometimes flexuous; mouth obtulely pentangu¬ 
lar ; vent Tometimes circular, Tometimes tranfverlely oval; 
■ the adjacent foramina Tometimes fhorter and fubovate, 
Tometimes longer, narrower, or linear ; avenues refembling 
ovate petals or leaves, confiding of a (ingle inner row of 
dots, and a row of oblique (trite penetrating the (hell, 
which is as thin as paper, and looks fomething like the 
pafte or dough that wafers are made of. The (hell appears 
made up of pentagonal pieces To nicely joined that Tcarcely 
any mark of a future is perceptible; and the(e pieces are 
full of little grains or protuberances not vifible to the eye, 
from which fpring minute (pines like the hair of a man’s 
beard. Yet the animal ufes them but little for motion ; 
the lower ones do not ferve for feet, but mod commonly 
for oars in fwimming. The oblong foramina mentioned 
above are very remarkable in. this and the two following 
fpecie-s ; they are cut entirely through the animal, fo that 
a ribbon may be put through ; the inlide lining of thefe 
holes is firm, and armed with (pines. Mouth and vent 
underneath. 
62. Echinus pentaporus, the five-holed fea-urchin: 
avenues emarginate at the tip ; vent near the mouth, with 
five foramina. Obtufely pentagonal; above whiti(h-a(h 
with a reddilh tinge ; beneath hollowed towards the mid¬ 
dle, white with a little yellow and blue veins; (hell witli 
prominent divilions; avenues oval ; mouth obtufely pen¬ 
tagonal, the lips a little prominent and perforated with a 
foramen ; vent nearly fquare, with adjacent linear and 
fuboval foramina; crown marked with a pentagonal dar. 
Of the five foramina, four are near the rim, almofl at 
right angles, the fifth is between two petals of the flower, 
confequently between two lobes, fo that one lobe is en¬ 
tirely (olid. Thefe large foramina are probably ufeful 
to the animal in riling and finking in the water ; for the 
refidance of the water, when part of it palfes through 
the holes, is not fo great as it would be againfi the entire 
(hell. The mouth and vent are very near together. 
63. Echinus hexaphorus, the lix-holed Tea-urchin : this 
is orbicular, with narrow avenues, and fix narrow fora¬ 
mina near the vent. Inhabits the Indian, American, and 
South, Teas, and very much refembles the lad : cinereous; 
crown umbilicate ; bafe a little hollowed, darker, and 
marked with frondofe lines. Thefe three lad are found 
in the Ead Indies, and (ometimes in the North Sea; but 
they are rarely feen, and very fcarce in cabinets on account 
of the thinnefs and brittlenefs of the (hell. 
64. Echinus emarginatus, or margined fea-urchin: 
nearly pentagonal, with ovate avenues; vent oval, more 
remote from the mouth, with fix foramina clofe to the 
margin. Inhabits the iiland Bourbon; greenilh-brown. 
Shell a (lightly heart-fliaped oval, a little pulvinate, (inu- 
ous, four inches and fix lines in tranfverfe diameter, crown 
patulous, bafe a little flatter, and marked with flexuous 
branched fculptured lines. 
65. Echinus auritus, or eared fea-urchin: margin waved, 
the lower one rounded, the upper one nearly fquare and 
twice divided, with an opening pore between every two 
of the avenues. Inhabits the Perfian leas; yellowifli-grey, 
the upper margin tawny ; the bafe flat, punftured, and 
marked with radiate firiae; vent oblong, and placed near 
the mouth. 
66. Echinus inauritus, or earlefs fea-urchin : fubcord- 
ate and adulate, the pieces hexagonal; avenues five, oval, 
emarginate at the tip, the fifth longer, and a pore between 
every two of them. Inhabits Amboyna, in the river Wag- 
nitoe ; five or fix inches high, and as many broad; the 
broader end thrice divided; thin and thickly covered with 
N U S. 
granulations fpinous at the bafe ; above reddifh-afli, be¬ 
neath violet-red. 
67. Echinus tetraporus, or four-holed Tea-urchin : orbi¬ 
cular, lightly famous., and perforated each fide with four 
foramina; vent circular. Pale yellow-grey ; crown wi-h 
five foramina ; avenues obtufe at the tip; the bafe fur¬ 
rowed with ten flexuous grooves bifid at the tips; mouth 
rounded and five-toothed. 
68. Echinus laganum : avenues oval, finely driate and 
cleft at the tip ; crown prominent; vent circular, and 
near the margin. Granulate, ochraceous, ovate, fubpen- 
tagonal ; the bafe with five excavated rays divided into 
fo many equal fpaces ; mouth obtufely pentagonal; vent 
hardly the breadth of a line diflant from the margin; 
crown perforated with five foramina between the avenues. 
69. Echinus fubrotundus : orbicular, with radiate ave¬ 
nues. Found hitherto only in a foflllt date. 
70. Echinus reticulatus : ovate, flattifli, with five oval 
avenues; the furface reticulate. Inhabits the American 
and Indian Ocean. 
71. Echinus orbicularis: circular, with oval acute ave¬ 
nues ; the bafe with ten imprefled porous rays ; vent mid¬ 
way between the mouth and margin, both circular. In¬ 
habits the Indian Sea. 
72. Echinus corrallatus : orbicular, with oval obtufe 
(liort avenues. Found hitherto only in a fofiile date. 
73. Echinus decadabtylos : diell perforated with four 
oblong foramina; the margin with ten teeth. Shell rough 
with granulations; above blueidi-green, varied with ci¬ 
nereous ; the avenues and futures pale fledi-colour; the 
bafe yeilowifh ,fledi-colour, with ten imprefled flexuous 
grooves, bifid at the tip and greenifli-afh ; avenues lanceo¬ 
late-oval, entire, biporous, united by oblique Arise; teeth 
of the margin alternately fhorter ; mouth rounded ; vent 
ovate. 
74. Echinus octodaftylos: the fore-part orbicular, and 
perforated with two foramina, the bind-part eight-toothed ; 
avenues lanceolate. Shell whitifh-adi.; adulate, the pieces 
convex ; crown umbilicate ; avenues emarginate. 
75. Echinus orbiculus : fore-part orbicular, entire; 
hind-part unequally toothed ; avenues lanceolate, cleft, 
and bent. Inhabits the Indian Sea. Shell flat, fuborbi- 
cular, not perforated, compofed of hexangular pieces; 
the bafe flat with imprefled grooves; avenues oval; 
mouth rounded ; vent oval. 
Ten avenues on the crown, the rays draight, biporous, 
and Aellate ; mouth and vent approximate ki the middle 
part of the bafe 76. Echinus nucleus : furface globu¬ 
lar, with an orbicular circumference ; bafe narrow, and 
flat in the middle; (ides grooved; avenues pulvinate; 
crown eccentric. Shell yellowilh-alh ; crown perforated 
with four pores; mouth circular; vent rather oblong, 
and (mailer than the mouth. 
77. Echinus centralis: lurface globular, circumference 
fuborbicular; bale pulvinate ; (ides very lightly grooved; 
avenues (lightly pulvinate; crown central. Perhaps a 
variety of the lad. Mouth very minute and orbicular. 
78. Echinus ervum : furface globular, circumference 
fuboval; bafe a little narrowed ; (ides grooved ; avenues 
fubpulvinate ; crown central. Larger than echinus nu¬ 
cleus; mouth and vent equal. 
79. Echinus craniolaris : furface globular on the fore¬ 
part, the hind-part nearly five-angled, pulvinate, and 
(loping; circumference elliptic; bafe a little narrowed; 
(ides grooved ; avenues pulvinate ; crown eccentric. In¬ 
habits the Indian feas : white, and covered with granu¬ 
lations furrounded with an engraved circle; crown with 
four pores. 
80. Echinus tur.cicus: furface and bafe pulvinate, cir¬ 
cumference elliptic ; fides hardly grooved ; avenues fub¬ 
pulvinate ; crown (lightly deprefl'ed and central. Pro¬ 
bably a variety of the preceding. 
81. Echinus vicia: furface globular, circumference 
obtufely oval; bafe a little narrowed ; Tides grooved 5 
avenues 
