et 
J. W. Bailey on a new Animaleule. 347 
connect the genus Amoeba with Difflugia, agreeing with the first 
in the soft body without shell, but differing in having true feelers 
or rhizopods confined to the anterior portion of their body, an 
by not throwing pseudopods from other parts. From Difflugia 
and the whole family of Arcellina, these forms are distinguished 
by having no lorica or shell. They are, however, closely allied 
to the Arcellina, and are very nearly what some of the species of 
this group would be, if deprived of their rigid external coverings. 
order to give to these curious beings at least a temporary 
name and place, I propose to found for their reception a new ge- 
hus named and characterized as follows, viz: 
PampHacus, nov. gen. 
Animals of the class of Rhizopoda (intermediate between 
Amoeba and Arcellina) without shell or lorica, and composed of 
asoft colorless matter easily extended by internal pressure, but 
hot spontaneously protruded into pseudopods. Feelers or rhizo- 
Pods, slender, numerous, radiant, branching and confined to the 
heighborhood of the mouth. ie: 
pecies 1. Pamphagus mutabilis.—This species, which is the 
only one now known, is sufficiently described above. Its habi- 
lat is probably the bottom of small pools and streams of fresh 
Water, as it was found in vast numbers in an aquarium supplied 
from such places in the vicinity of West Point.. It will proba- 
bly be found to be a common form, and as it presents the condi- 
lions of animal life in almost the lowest degree of simplicity, 
and can be preserved and studied with great ease, it will well re- 
Ward the attention of microscopists. I have thousands of these 
animals now living in mid-winter, and with a little care they 
ay probably be kept until the return of warm weather, when 
other interesting facts may possibly be added to the observations 
here recorded, The sketches above given, except figs. 34 to 39 
Inclusive, are all drawn to the scale on page 341, which shows 
ten one-thousandths of an inch equally magnified with the draw- 
‘ngs. These sketches were all made by means of a camera 
lucida eye-piece attached to the microscope. ‘The objective em- 
Ployed in making these drawings was a new one of surpassing 
*xcellence, of 4 inch focal distance, made by Spencer. 
West Point, N. Y., Jan. 14, 1853, 
