270 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 
demi-canal, paved in the same way with cells as the chambers them- 
selves. 
Not seeing the sponge in an absolutely fresh condition, I could not 
observe the action of the funnels in life; but once while the whole sponge 
was still in a comparatively fresh condition, and under observation in a 
zoophyte trough, I saw one of the inverted funnels suddenly everted and 
expanded to apparently its fullest extent. I was also unable to detect 
the slightest evidence of any other kinds of openings besides the funnels 
into the organism, and these were of about the same size throughout. 
This fact, together with others which I have stated, removes all doubt 
as to the sponge nature of the organism. 
There is no form known to me in literature which corresponds to this 
in structure. Halisarea does not have a tough membranous ectoderm, 
while the Physemaria have an ecto-skeleton, composed of the shells of 
Foraminifera. But as the existence of the Physemaria has been appar- 
ently doubted by some zoologists, the position of Camaraphysema becomes 
an interesting question. At any rate it may be safely placed close to 
the fleshy sponges, and may possibly constitute a distinct family. 
The account now offered, while it is not as complete as might be de- 
sired, rests upon sufficient evidence to make it desirable that the fullest 
possible description of the organism should be put upon record for the 
benefit of those who may have the opportunity of extending or confirm. 
ing my interpretation of its anatomical and embryological features. 
While I could hardly convince myself at first that I did not have before 
me some one of those curious compound Ascidians of the suborder . 
Synascidice, the absence, however, of a common cloacal cavity and any 
indications of a branchial apparatus or a digestive canal satisfied me 
that IL was not dealing with a tunicate, but that I should have to look 
among the very lowest of the sponges for its nearest affines. 
I have stated that no collar or flagellum could be detected as forming 
the inner extremities of the cells lining the cavities. This fact does 
not, however, render it improbable that such structures exist in the liv- 
ing animal, as it must be borne in mind that both Bowerbank and Carter 
have called attention to the circumstance that the flagellate cells of 
sponges withdraw their collars and flagella after death. The extreme 
irritability of sponges is notorious, and to one who sees it for the first 
time would be considered remarkable, and it is not unlikely that Cama- 
raphysema partakes of this characteristic, known to be well-nigh common 
to all the members of the group. 
The exact locality from whence this species was derived could not be 
ascertained; all that the writer could learn was that the lot of oysters 
from whence he had obtained his specimen had certainly been brought 
from the waters of the Chesapeake. It is to be hoped that more speci: 
mens will be brought to light, as the writer in investigating his unique 
specimen was obliged to sacrifice it in order to make his study as com- 
plete as possible by slicing it up into sections. 
