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BULLETIN OE THE UNITED STATES EISH COMMISSION. 
Genus STELOSPONGOS 0. Schmidt (1870). 
Fibers of the skeletal network comparatively stout; distinct radiating bundles (fascicular fibers) 
always developed, in which, radial main libers and short transverse connectives may be distinguished. 
Stelospongos sp. 
Station?, one specimen. 
I am unable more exactly to identify a macerated skeleton, having the shape of a flattened 
irregular mass 210 by 70 mm. with a thickness of 20 to 40 mm. I append the following description 
for the use of those who may collect in the Porto Rico waters: 
Body consists of trabecuke and plates anastomosed together with irregular spaces between. 
Surface in places covered with conuli 1 to 2 mm. high, and about 2 mm. apart, which may be arranged 
in rows; and which in such regions may fuse more or less completely to form imperfect ridges. Between 
the conuli lie the closely set round openings, 1 to 2 mm. in diameter, of canals running vertically to 
surface. Elsewhere conuli are absent; and here are found closely set oscula about 2 mm. diameter, the 
bounding wall of each osculum being a short tubular projection about 1 to 2 mm. high. Transitional 
stages between these two conditions are found, from a consideration of which it becomes plain that 
the tubular oscular projections are formed by a fusion of conuli. 
In still other regions, in place of the conuli or oscular projections, the surface may exhibit grooves 
1 to 2 mm. wide and deep, sometimes mseandriform. Such grooves are here and there imperfectly 
covered over by a few fibers. On the bottom of the groove the round openings of canals may be seen, 
or the groove appears as the oblique superficial continuation of an oscular aperture. 
Conuli are the extensions of the fascicular fibers. Wall of oscular tube made up of closely set 
fascicular fibers with looser network between. A very loose open network of libers, with meshes 
plainly visible to the eye (up to 1 mm. diameter) extends superficially between the conuli or oscular 
projections. The fascicles include radial, more or less parallel, fibers about 50 n thick, some of which 
(sometimes one, sometimes more) are cored with spicule fragments, sand grains, and foraminifer shells. 
Between these run short, simple connecting fibers, often about 20 ju thick, commonly giving rise to a 
scalariform arrangement. Skeletal network of interior with irregularly polygonal meshes; diameter 
of fiber commonly 40 to 50 //. Foreign inclusions found only in the radial fibers of the fascicles. 
Consistency, for a horny sponge, hard and rigid. Color of skeleton, light brown. 
Genus HIRCINIA Nardo (1834). 
Skeletal reticulum in general coarse, meshes 0.5 to 3 mm. wide; tracts of finer reticulation may 
be developed. More or less fascicular radial (main) fibers always present; and parts of internal 
network may also become fascicular. Fascicular fibers vary from a nearly simple condition, in which 
the horny mass of the fiber exhibits scattered mesh-like perforations, to a state in which the 
perforations are so numerous and large as to give the fiber the character of a bundle. Filaments 
present in the parenchyma. 
Hircinia acuta (Duchassaing et Michelotti) Hyatt. 
Polytherses acuta, Duchassaing et Michelotti, 1864, p. 72, pi. xiii, fig. 3. 
Hircinia acuta, Hyatt, 1877, p. 548, pi. xv, figs. 20, 21; pi. xvir fig. 26. 
Station?, two specimens. 
Smaller specimen massive, irregular, about 50 mm. high; with one osculum, 2 by 3 mm., on the 
upper surface at apex of rounded protuberance; four smaller oscula flush with the surface on one side. 
Larger specimen also massive, 100 mm. high with transverse diameter of 50 mm.; two oscula about 
3 mm. diameter at apex of truncated conical protuberances on upper surface; one smaller osculum at 
apex of fistular protuberance on upper surface. From the bases of the prominent conuli radiate lines, 
the most conspicuous of which are ridges which pass from conulus to conulus, thus dividing the 
surface up into a system of polygonal depressed areas, diameter of which may be as great as 20 mm. 
(Hyatt). In the Porto Rico specimens conuli are about 2 mm. high, 4 to 6 mm. apart; frequently 
divided, as Duchassaing et Michelotti state, at the summit into two or three very small projections, 
each of which marks the termination of one of the ridges separating the surface areas. Dermal mem- 
brane very tough. Subdermal cavities, often about 2 mm. diameter, fairly abundant; in places so 
