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PROGRESS OF MICROSCOPICAL SCIENCE. 
named 0. lapsa is the same as the preceding. A variety has been 
observed in several instances in which the animal had a single pair of 
appendages springing from a common root. 
Ouramoeba hotulicauda. — This species is predicated on the form 
alluded to in my previous communication as having a single tuft of 
three moniliform rays. I have seen it a number of times since, and its 
characters appear to be sufficiently constant to recognize it as a 
distinct species. It is much smaller than the preceding. The body 
measures about the -^^ of a millimeter. The appendages are usually 
in a tuft of three ; each appendage consisting of from one to three 
sausage-like joints. Found with the preceding. 
A curious Bhizopod : Biomyxa vagans. — Professor Leidy, who has 
recently been directing his attention to this branch of zoological 
research, remarked,* that in some water with aquatic plants, from 
Absecom Pond, N. J., preserved in an aquarium during the winter, he 
had detected a remarkable rhizopod, which he thought might best be 
compared to the reticular pseudopods of a Gromia separated from 
the body. The creature moved actively and assumed the most varied 
forms. At one time it appears as a cylinder or a ball of jelly which 
may spread itself into a disk of extreme thinness, from the edge of 
which emanate a multitude of delicate pseudopods minutely ramifying, 
and with the contiguous branches anastomosing, as in the extension 
of the net of a Gromia. At other times the creature divides up into 
branches from a trunk in the manner of a tree, but with the con- 
tiguous branches anastomosing. At times also the animal assumes 
the form of a cord, and the jelly accumulating along some portion of 
it will then move along the apparent cord like a drop of water running 
down a piece of twine. The branching pseudopods extending into a ■ 
net, the large angular meshes gradually contract by the widening of 
the cords, so that the meshes become perfectly circular and appear 
like vacuoles imbedded in the jelly. A circulation of jelly with 
granules is observed along all the pseudopodal filaments exactly as in 
Gromia. No trace of a nucleus or investing membrane in any posi- 
tion could be detected, but the protoplasmic structure contained a 
multitude of minute vacuoles. Most of the specimens contained no 
food, and only one of the largest was observed to contain numerous 
minute Closteria. 
The largest specimen, consisting of a net emanating from three 
divisions, occupied a semicircular space of f of a mm. by f mm. 
Another specimen with a central disk ^ mm. by ^ mm. with its net, 
occupied a circular space f mm. in diameter. A small cord-like speci- 
men was mm. long with an expanded end gL- mm. wide ; and another 
irregular cord-like specimen was f of a mm. long with the widest 
portion mm. 
Amoeba porreda, of Schultze, from the Adriatic Sea, most resembles 
the creature described. While it is nearly related with Gromia, 
Licbcrkuehnia, VampyrcUa, Nuclearia, &c., it appears sufficiently 
distinct in its characters to represent another genus, and with the 
species may be appropriately named Biomyxa vagans. 
* 'Proceedings of the Philadelphia Academy/ April 20, 1875. 
