166 BULLETIN OF THE BUREAU OF FISHERIES. 
Topsent some years ago (1905, p. CLXXXV) described a new and interesting sponge 
for which he created the genus Pleraplysilla. Topsent’s sponge, P. minchini, was dredged 
off the French channel coast at a depth of 30 meters. The sponge is incrusting, about 1 
millimeter thick, except in spots where the thickness reaches several millimeters. The 
color is chocolate. The largest specimen measured 25 centimeters in diameter. The 
surface is beset with conuli 1.2 to 2 millimeters or more apart. ‘The skeletal fibers are 
characteristically simple but, especially in the thicker parts of the sponge, may send out 
two or three branches; they are too to 110 p» thick below. The flagellated chambers 
are eurypylous and measure about 90by 35 uw. The Beaufort sponge is evidently another 
species of this genus. 
For Pleraplysilla and another sponge Igernella (Darwinella) joyeuxt, from the Gulf 
of Mexico, Topsent, Joc. cit., creates the family Pleraplysillide. Igernella having horny 
spicules would be a good Darwinella if the fibers of its skeletal reticulum were not 
areniferous. But this latter characteristic excludes it from the Darwinellide (Aplysillidee 
of some). Its horny spicules, on the other hand, exclude it from the Spongelide. The 
sponge is an intermediate between the Darwinellide and Spongelide, and Topsent’s 
family provides a place for it, although, if Pleraplysilla is removed, as we suggest (see 
below), the name of the family will have to be changed. 
Pleraplysilla, while it will not go in the Darwinellide because of its areniferous 
fibers, can not, it seems to us, be excluded from the Spongelide. It takes its place at 
the base of the latter family, its very simple fibers leading up to the more complicated, 
but still independent, ones of Spongelia spinifera. It is generally recognized that the 
separation between the Darwinellide and the Spongelidz is not a sharp one. Dendy 
(1905, pp. 203, 207) points out that Spongelia spinifera F. E. Schulze and Megalopastas 
Dendy are intermediate forms. Igernella and Pleraplysilla are also intermediates, 
although not intermediate in respect to the same points. 
Family SPONGIDA. 
Sponges with small flagellated chambers, 20 to 50 u wide, and a skeleton, generally 
in the shape of a reticulum, composed of solid or pithed, horny fibers. 
Subfamily STELOSPONGINA. 
Spongide in which main fibers and connectives are generally distinguishable in the 
skeletal reticulum. The main fibers may be simple but are generally more or less 
fascicular. Between the fascicular fibers, or between the simple main fibers in species 
without fascicles, the skeletal meshes are much larger than in the Euspongina. 
Hircinia Nardo. 
Stelosponginz with filaments in the ground substance and in which the connectives 
are characteristically attached to the main fibers by diverging roots which extend along 
the main fiber in one plane. 
Hircinia ectofibrosa, n. sp. (Pl. LXIV, figs. 41, 43, 44; Pl. LXVI, fig. 61.) 
Taken several times on Fort Macon beach after moderate gales; six specimens available for study; 
probably growing on the “Fishing Bank’’ off Beaufort Inlet and in similar places, and to be looked 
on as an outlying member of the Florida-West Indian fauna. 
