136 BULLETIN OF THE BUREAU OF FISHERIES. 
a large efferent canal extending more or less radially into the sponge substance. The efferent canals 
in this specimen are somewhat smaller than, and not so close together as, the corresponding incurrent 
canals; but this is a matter of individual variation. 
Numerous very small subdermal cavities, covered in by dermal membrane, underlie the cloacal 
surface between the oscula. Some are circular and about 80 w in diameter; others are elongated and 
about 2zoopmacross. From them small canals, often about 80 u in diameter, pass radially into the interior. 
(Sponge being shrunken, such dimensions are, of course, far from what they must be when the sponge 
isexpanded.) ‘The areas of dermal membrane covering in the subdermal cavities are thin and in life 
are doubtless perforated by the (now closed) pores. In correlation, perhaps, with the completely 
closed condition of the pores and the contracted state of the sponge these areas now contain megascleres 
scattered tangentially. The inference to be drawn from the anatomy is that the cloacal surface is not 
an exclusively excurrent surface. 
Spicules.—Megascleres: (1) The characteristic spicule is a tylostyle (fig. 49c), smooth, slightly 
curved, about 350 by 8. The common range in length is 325 to 425 uw’ in thickness,7 to1z uw. The 
head may be evenly rounded, or it may be somewhat elongated and bear a constriction. Modifications 
of this spicule sometimes occur in the form of (2) tylostyles (fig. 49a), in which the apex is not pointed, 
but rounded, and (3) styles (fig. 49h). Microscleres: Spirasters (fig. 49d), 8 to 20 » long, of one or two 
complete ‘‘turns.’’ ‘The spines are short and conical, sharp in some spicules, truncated and blunt in 
others. The spicules oceur at the dermal and cloacal surfaces and in the walls of the canals. They 
are abundant, but not very abundant; nowhere do they form a continuous layer or “‘crust,’’ but every- 
where they are spaced well apart. The common range of length in the spicules at the dermal and cloacal 
surfaces is 8 to 12 uw. In the walls of the large canals they reach 20 yw in length. 
Skeletal framework.—The septa of spongs tissue between the canals are well filled with megascleres 
except in the region immediately around a canal. In places the megascleres lie crossing one another 
in all directions. But in many septa, both thick and thin, the spicules alt lie about in the same direc- 
tion and are compactly arranged, thus constituting a fairly distinct tract. Different tracts cross one 
another at various angles, connecting and branching, and thus give to the skeleton a fibrous appearance 
which is inconspicuous in alcoholic, but conspicuous in dried, material. In the canal walls the mega- 
scleres are strewn thickly and tangentially. 
At the dermal surface, while there are some tangentially placed spicules, the bulk of the mega- 
scleres occupy an obliquely radial or radial position, their points projecting; but they are not divided 
into distinct brushes. They form a continuous covering, which is only interrupted by the large, 
incurrent apertures and the areas of membrane over the small, subdermal cavities. 
At the cloacal surface also many megascleres lie radially and obliquely, projecting slightly. At 
this surface there is in this specimen a particularly dense skeletal layer, about 1 millimeter thick, in 
which the spicules lie in all directions. This is a detail which is not present in all the specimens. 
The first specimen of this species studied by us was collected a number of years ago in Jamaican 
waters by Prof. E. A. Andrews, of Johns Hopkins University. Some data concerning this specimen 
may be recorded here. ‘The characteristic size of the tylostyles is 420 4 by 144. The spirasters at the 
dermal surface are commonly about 14 » long and are more abundant than in the Beaufort specimen, 
forming a continuous crust. In the walls of the larger canals they reach a length of 20 yu. 
In the dried fragment of this specimen sent us for examination, the incurrent apertures of the dermal 
surface were for the most part filled with what were doubtless small anemones. Dendy records (1896, 
p. 252) that in S. papillosa R. and D., occurring in the neighborhood of Port Phillip Heads, Australia, 
“the surface is sometimes much infested by a parasitic actinozoan.”’ 
The habitus of the Jamaican specimen as recorded by Prof. Andrews is interesting: ‘‘Height of 
sponge, 2 feet; diameter, 11 inches; diameter of mouth, 4 inches; depth of cloacal cavity, 10 inches. 
Sponge stood upright on a reef 20 feet below the surface. In life the color was black or perhaps purplish 
black, very dark brown when dried. When alive, sponge was covered with peculiar small objects 
which seem to be actinians, partly embedded in the surface, each 1 millimeter in diameter. Sponge 
hard, smooth, compact.”’ 
The Albatross specimens in the National Museum “‘average 18 inches in diameter, 12 inches high; 
cylindrical in shape, but with deep cavity in top.’’ (Letter from Dr. Mary J. Rathbun of the U. S. 
National Museum.) A particular specimen measured 30 centimeters high by 40 centimeters in cross 
diameter; cloacal cavity 15 centimeters deep, 25 centimeters across at the mouth. The sponge (dried) 
