y Set 
742 LIFE HISTORIES OF THE PROTOZOA. 
leaves of fresh-water plants. The late H. J. Clark, our most emi- 
nent microscopist, thus describes its habits in his “ Mind in Na- 
ture.” “The three figures represent the various forms which I 
have seen the same individual assume, whilst I had it under the 
microscope, as it crept over the water-plants upon which it is 
accustomed to dwell. The most usual form which it assumed is 
that of an elongated oval (A), but from time to time the sides of 
its body would project either in the form of simple bulgings (B), 
or suddenly it would spread out from several parts of the body 
(C), as if it were falling apart; just as you must have seen a drop 
of water do on a dusty floor, or a drop of oil on the surface of 
water; and then again it retracted these transparent arms and 
became perfectly smooth and rounded, resembling a drop of slimy, 
mucous matter, such as is oftentimes seen about the stems of 
aquatic plants.” 
Pelomyxa (Fig. 134) is a fresh-water Ameba-like form, but,pro- 
vided with spicules. Under the name of Amoeba sabulosa Prof. 
Leidy deseribes* a form which he thinks “is probably a member 
of the genus Pelomyxa,” and which is characterized by the com- 
paratively enormous quantity of quartzose sand which it swallows 
with its food. “The animal might be viewed as a bag of sand! 
It is from one-eighth to three-eighths of a line in diameter, and 
was found on the muddy bottom of ponds in Pennsylvania an 
New Jersey. Itis possibly Pamphagus mutabilis, figured by ye 
fessor Bailey in the “ American Journal of Science and Arts, i 
1853. Another form resembling Greef’s Pelomyxa, and found 
by. Professor Leidy in a pond in New Jersey, is Deinamæba 
mirabilis ;+ its body bristles with minute spicules. He has alad 
described in the same Proceedings (p. 88) Gromia terricola, which 4 
lives in the earth about the roots of mosses growing in the crev 
ices of the bricks of the pavements of the streets of Philadelphia. 
He thus graphically describes this singular form. “Imagine an 
animal, like one of our autumnal spiders, stationed at the oen 
of its well spread net; imagine every thread of this net to be® 
living extension of the animal, elongating, branching, and becom 
ing confluent so as to form a most intricate net; and he 
every thread to exhibit actively moving currents of 4 viscid "a 
both outward and inward, carrying along particles of tondi - 
* Proceedings of the Academy of Natural Sciences, Philadelphia, 1874. P- % 
IL e. p- 142. a 
