
MARINE AQUARIA 

with flat granules, and fringed with thick obtuse spines. The under side 
is covered with regular rows of quadrangular plates. The color is vari- 
able, usually variegated and spotted with purple. It is a large species, 
about 18 inches in diameter, and may be found in shallow water along the 
entire Northern Atlantic coast. 
Ophiothrix angulata, (Ver.), is a small Florida species, sometimes 
found farther north. The body is covered with short rough spines, and 
the five arms are narrow, tapering and beset with long spines serrated on 
the edges and ends. The color may be pinkish-yellow or light-brown, 
according to the bottom upon which it lives. 
Amphiura squamata, (Ver.), is a small 2 to 4 inch diameter animal. 
The body is less than 1% diameter, and the five arms threadlike and al- 
most smooth on their surface. This is a delicate species found from New 
Jersey northward below low-water marks. 
Sea Urcutins. These animals are closely related to the Starfishes, 
the shell-like covering showing the lines of union of the rays. They are 
mostly deep-water forms, the two shallow-water species on the Middle 
Atlantic States coast are: 
Arbacia punctulata, (Ver.), having a one inch in diameter shell with 
14 to 34 inch long spines. The color varies from straw-yellow and white- 
ish-grey to brown, with the spines tipped with brown. A small species 
found in shallow water from Massachusetts to Florida. 
Strong ylocentrorus drobachiensis, (Grey,) the Common Sea-egg, has a 
2 inch in diameter shell, greatly resembling a large chestnut-burr, usually 
of greenish-purple color. The body is circular and sometimes depressed, 
and the tube-feet slender. It moves slowly and feeds on small alge, 
oscillatoria, and decaying animal matter. Common in shallow water along 
both the Atlantic and Pacific coasts, most abundant on the coast of Maine. 
Both these forms are harmless and useful aquarium inmates. 
Sanp Dotiars or SHietD Urcains. ‘This urchin, of which the 
circular disc forming the skeleton, is a common object on some beaches, 
belongs to the genus Echinarachnius, of which one species occurs in 
Middle Atlantic coast waters. 
Echinarachnius parma, (Stimp.) has a skeleton consisting of a flat disc 
composed of calcareous matter and sand, often 4 to § inches in diameter, 
which in life is covered by short silky spines. The animal ts somewhat 
like a jellyfish in general form, occurs in deeper water, and is very rarely 
taken near the shore. 
Sea Cucumsers. ‘These higher forms of Echinoderms are native to 
warm waters, and but one species occurs on the Middle Atlantic coast. 
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