A STUDY OF SOME EPITHELIOID MEMBRANES IN 
MONAXONID SPONGES 
H. V. WILSON 
Professor of Zoology in the University of North Carolina 
TWENTY-ONE FIGURES 
In the course of some experiments dealing with the regenerative 
power of the tissues in certain monaxonid sponges, it became neces- 
sary to learn the histological peculiarities of the epidermis in these 
forms. It soon developed that the adult epidermis in these 
species did not conform to the type usually thought of as well 
nigh universal in sponges. A study of the regeneration of the 
epidermis in cuttings was then undertaken, rather with the idea 
of its throwing light on the adult structure. During the study 
of the epidermis some new facts as to the way in which pores 
close were made out. Finally for the purpose of comparison 
with the epidermis, the canal epithelium in a suitable species was 
studied. 1 
THE EPIDERMIS IN STYLOTELLA 
The most abundant sponge in Beaufort harbor is Stylotella 
heliophila, a form which I have described in a paper now in press 
for the U. S. Bureau of Fisheries. The genus falls in the hali- 
chondrine monaxonida. The sponge has well marked ascending 
lobes of conical shape which bear terminal oscula. The pores 
are scatttered over the whole surface. Spaces of considerable 
size (subdermal cavities) belonging to the afferent system lie 
' The work was carried on during the summer of 1909 at the Beaufort Laboratory 
of the U. S. Bureau of Fisheries. My thanks are due to Hon. Geo. M. Bowers, 
U. S. Commissioner of Fisheries, for a place in the laboratory, and to the Direc- 
tor, Mr. H. D. Aller, for his kindly aid during my stay. 
