cclxxvi 
Echinodermata. BADIATA. Asteroids. 
Class-ECHINOD ERM A.T A— {Spiny Skim ) . 
'I'liis, the lii^liest form of Hadiata, includes five 
orders : Jlolothnrians, Echinoids, Asteroids, Ophiu- 
ridiis and Grinoids. 
IIOLOTHURl A.NS — (Sea-cucumbers). 
One species of Ilolotliuria, found on tlie Florida 
Reef, is much like that used by tlie Chinese, and 
called 'I’repang. 'I’his species has a i)eculiar and 
very strange parasite. It is found when the IJolo- 
thuria is lifted from the water, or after it has been 
kept out of water for a few minutes, that there is a 
Fish within its alimentary canal. If the Holothuria 
is placed in water, fresh, it soon disgorges the seem- 
ing intruder, which is a purely natural parasite. 'I'he 
Fish is about five inches long, of a pearl color and 
transparent, the internal parts being easily seen 
through its sides. 
PENTACTA (Pentacta frondosu) is a very rare 
form, excepting on the colder poi tions of the shore. 
At Grand .Menan they are abundant upon the I'ocks 
near low-water mai'k. 
CUVIERIA [Cuvieria sqxiamnata) is the most beau- 
tiful of the Holothurians. A coating like mail, of 
imbricated plates of lime, covers nearly the whole 
body ; a flat surface being left free and smooth upon 
which the animal glides in locomotion. On this flat 
surface are three of the ambulacral rows only. 'I'he 
plates, which cover all other portions except the 
mouth, are of a beautifid scarlet color, or, in some in- 
stances, a deep crimson. When taken from the water 
this creature, like the Polyps, contracts and draws 
within all the soft parts, but when undisturbed it 
produces from its mouth an arborescent wreath quite 
as long as the body itself, and of great beauty of form 
and color. The young are found swimming about 
freely, and are of the same brilliant vermilion color. 
On the New England coast the Cuvieria is not a 
familiar object, as it is found in deep water. The 
fishermen occasionally bring them up on their lines, 
and they are often found in the stomachs of Fishes. 
'I'he young that are just developing the limestone ar- 
mor are found plentiful under the stones at low-water 
mark. 
CAUDINA (Caudina arenata) is one of the most 
abundant, yet it is seldom seen except after heavy 
storms, when it may be found in great numbers upon 
the sandy beaches of New England. It lives in the 
sand. By some it is compared to the human finger, 
on account of its resemblance in shape and color. 
The mouth is a simple aperture in the middle of the 
truncate head. 'I'he latter is bordered by a row of 
short clove-shaped tentacles. 
SYNAPTA [Synapta tenuis). — 'I'his form is long 
and cylindrical, with a curious transparency which 
allows the internal structure to be seen distinctly. 
'I'he mouth is fornnid like a^ circular tube, which en- 
closes a row of arborescent tentacles. For so deli- 
cate a creature its food is peculiar, consisting of sand 
and shells; the nutritious matter being digested and 
the coarser portion ejected. 'J'he body is often sev- 
eral feet in length, and is shortened frequently by tlie 
separation of portions of its posterior parts, as seen 
in the case of the Star-fishes. 
E 0 H 1 NO 1 D S — (Sea-urch ins) . 
'I’he Sea-urchins have a more or less spherical or 
discoidal shell, composed of plates that bear tubercles 
on which spines are articulated. 'I'he surface is com- 
posed of ten zones of two widths, alternating. 'I'he 
spines are mostly borne on the larger zones, and the 
narrow ones bear the suckers. 
SEA-URCHIN (Toxopneustis drohacMemis) is one 
of the most familiar species of the Echinoderms. It 
is abundant on the coast of New England, where it 
is known as the Sea-egg, being found at low tide on 
the rocks and along shore. Like many of the Fishes 
their size increases as the colder regions are reached. 
They are usually known as a moiety of the great 
masses of ocean debris thrown upon the beaches after 
heavy storms. 'I'hey have a habit of covering them- 
selves with sea-weed, which serves to conceal them. 
ECHINARACHNIUS (Echinnrachnius pnrma ). — • 
'I’his form is not so familiar. 'I’o those who frequent 
sandy beaches it is known as “Hand-cake,” being flat 
and round. 'I’he color is dark brown, and the spines 
are very small and silky. 'I’o many it is known oidy 
as a perfectly smooth, flat, round shell, having a won- 
drously regular sculpture on its more convex surface, 
the minute spines being easily rulibed olf, esjiecially 
after the death of the animal. ProbabI}' no form on 
our shores so mystifies the observer; the extreme 
thinness of the creature naturally [irecludes the idea 
of a living thing; yet, the same organs are there — 
the ambulacral tubes or suckers — and the interior is 
on the same plan as that of the Sea-egg. The teeth 
of this species are not so complicated by muscular 
apparatus. 
AS'l’EROIDS — (Star-fishes). 
In the structure of the Sea-urchin it is seen l.hatat 
the termination of the zones, near the mouth, are the 
eyes. In the Star-fish we find the eye#, one upon 
each ray, at the end — as if the rays of the Urchin 
had only to be unfolded and flattened to constitute a 
Star-fish ! 
STAR-FISH (Astracanthion berylinus) is the most 
common form on the New England coast; being 
abundant in eveiy bay or arm of the sea, where 
it is seen clinging to the rocks just above low tide. 
Pink vHtak (A. pallidus), the oidy other species of 
this genus, is much less familiar, as it is found in 
deeper water. 
CRIBRELLA (Orebrella oculata) is a small Star, 
inferior in structural rank to the preceding, but beau- 
tiful in color, some having a rich 'I’yrian purple, 
others a vermilion or bright orange. 
HIPPASTERIA [Hippasteria phrygiana). — 'I'liis 
is a rare form ; occasionally fishermen bring up living 
specimens from deep water, and they are sometimes 
found on the beaches after heavy storms in the win- 
ter months. 'They are not armed with the s|)ines so 
common to the ordinary Star-fishes, but have smooth 
warts. 'I’lieir color is usually a brilliant vei'inilion. 
