232 MARINE INVERTEBRATES 
Genus Pentacta 
P. frondosa. This animal is commonly called the sea-cucumber, 
and the popular name somewhat expresses its form, but it has the power 
of changing its shape in a most surprising manner. Sometimes it will 
be nearly globular, again long and thin, 
or it may be constricted like an hour- 
glass. When at rest the body is ovate 
and somewhat pentagonal. On the an- 
gles are double lines of suckers, and 
in the interambulacral zones are a few 
scattered false ambulacra. The surface 
is nearly smooth, very dark purple on 
one side, and inclined to whitish on the 
other. Ten much-branched tentacles 
surround the mouth. The animal, when 
grown and expanded, measures fifteen 
to eighteen inches in length. This 
species is found throughout the whole 
length of both the east and the west 
coasts. Itis very plentiful on the Maine 
coast in tide-pools and on the rocks at 
Pentacta frond the sea-cucumber. 
over the greater part of the 
globe. The tough muscular 
body is said to be edible, tasting 
somewhat like lobster, or tre- 
pang (Holothuria edulis), which 
is found on coral reefs in Hast- 
ern seas and is much valued as 
food by the Chinese. The internal organs 
of P. frondosa are highly colored, making 
its anatomy easy to trace. The muscular 
system is plainly defined. 
Genus Lophothuria 
L. fabricié (Verrill), Psolus fabricii 
(Diiben), Cuvieria squamata (D. and 
K.: Agassiz). The body in this species 
is covered with rounded overlapping scales 
and numerous granulations, and when it 
low-water mark. The genus ranges 
isretracted is about two and a half to three ropnoturia fabricii, showing under sur- 
inches long and about one inch thick. 
face with three rows of ambulacra. 
