SPONGES OF BEAUFORT (N. C.) HARBOR AND VICINITY. 149 
lation may be limited to the head, or small spines may be present over a part or a whole of the shaft. 
(2) Strongyle, of about same size as the style but much less abundant; obviously a modification of it. 
(3) Ectosomal tylostyle, commonly straight, slender, and cylindrical, sharp-pointed, head slightly 
tylote, 120 to 140@X24. Present but not at all abundant in the ectosome, where it is placed radially 
or obliquely, usually projecting. Microscleres: (4) Isochela with twisted axis, 9 to 11 w long; fairly 
abundant in the parenchyma; very abundant in spots in some specimens. When one tooth is seen in 
ventral view the other appears more or less in side view. Occasionally the rotation is greater, and both 
teeth are seen flatwise, one in ventral, one in dorsal, view. Normal chele, in which the axis is not 
twisted, also occur, but very rarely. The spicules are small and delicate, requiring to be studied with 
an immersion objective. In a foreshortened view the terminations appear as more or less circular cups 
on opposite sides of the apparently short axis. (5) Toxa, 20 to 60 2 long, in parenchyma, less abundant 
than the chela. 
Skeletal framework (P1. LX, figs. 22, 23).—Principal fibers and connectives are distinguishable. The 
former are primarily longitudinal, branching as they ascend, the branches curving out radially toward 
the surface. These fibers are polyspicular; the spicules arranged lengthwise or somewhat obliquely, 
and for the most part completely embedded in spongin. A few spicules project here aud there at right 
angles to the fiber, doubtless representing connectives that will develop. 
The longitudinal fibers are about 30 to 60 #7 thick. They include 3 to 8 lines of spicules as seen in 
optical longitudinal section of the fiber. Transverse sections show that the actual number of lines of 
spicules ranges in different specimens from about 3 toas many as 20. The radial parts of the fibers have 
usually 2 to 4 lines of spicules. 
The connectives are mostly one spicule in length, sometimes two, and at about right angles to the 
principal (longitudinal or radial) fibers. They include 1 to 2 rows of spicules, sometimes as many as 
three rows, when all or all but one row are quite slender. The spicules are well covered with spongin. 
Meshes often longer than wide, rectangular; or squarish. While the style is the chief skeletal spicule, 
the strongyle is very common in the connectives and perhaps predominates in them. 
In the ectosomal region, including a thickness of about 350 u, the principal fibers are somewhat closer 
together than in the interior, and there are more connectives (Pl. LX, fig. 22). The skeleton is thus 
denser in this region. ‘The radial fibers project slightly beyond the surface of the sponge, the terminal 
spicules diverging and projecting beyond the spongin of the fiber. 
The dermal membrane is supported by the most superficial connectives, which extend between the 
outer ends of the radial fibers. These dermal connectives have the usual character; that is, they com- 
monly have the length of one spicule, sometimes of two; the included spicules, one or two rows, are 
entirely embedded in the abundant spongin; common thickness of connective, 12 to 16 4; mesh squarish 
or polygonal. Here and there a spicule with its base rooted in the connective projects, at right angles 
to the latter, beyond the surface of the sponge. 
There is considerable quantitative variation both in the skeletal framework and the megascleres. 
Thus, in the same specimen the framework is somewhat denser in the older than in the uppermost part 
of a branch, owing largely to the fact that the connectives are more numerous and, perhaps, somewhat 
thicker. The differences between the several specimens in respect to these points are noticeable, 
although vague. In those of the chaliniform type (Pl. LX, fig. 21) the principal fibers are slenderer 
and the skeletal styles perhaps slenderer than in the other specimens. ‘Thus, in one of the chaliniform 
specimens the range in the actual number of rows of spicules contained in the longitudinal fibers is 
about 3 to 8, whereas in the biseriate specimen (Pl. LX, fig. 20) it is 4 to 20. In one of the clavate- 
spatulate specimens the skeletal style is very often noticeably stout and fusiform. But these stout 
styles are accompanied by a great many quite slender ones. 
The Beaufort sponge is not far from Esperiopsis anomala R. and D. (Ridley and 
Dendy, 1887, p. 84), a ramose sponge from Honolulu, in which there is a rich develop- 
ment of spongin, producing a chalinine appearance. Ridley and Dendy remark on this 
fact that it “forms a very good instance of the manner in which horny fiber may be 
developed in any genus.’’ Other species of Esperiopsis in which horny fiber is exten- 
sively developed are E. symmetrica R. and D. from off Port Jackson (Ridley and Dendy, 
1887, p. 79), E. (Amphilectus) hispidula (Ridley) from Torres. Strait (Ridley, 1884, 
