SPONGES COLLECTED IN PORTO RICO. 
403 
nearly smooth. In the lining membrane of the vestibular spaces are many groups of pores, but they 
are not so numerous as in Schulze’s figure of the, in many respects, similar form Cacospongia cavernosa 
(1879«, Taf. xxxvii, fig. 14); nor are the individual groiqis (pore-areas) so well defined. Frequently, 
in place of a group of small apertures, there is one comparatively large opening. Flagellated chambers, 
25 to 30 ju diameter. 
Skeleton. — The macerated and dried skeleton is hard, though compressible and elastic; reddish 
brown externally, lighter inside, and especially light on attached surfaces. Skeletal network consists 
of fibers mostly about 40 /. i diameter, without inclusions, forming polygonal meshes; diameter of typical 
mesh, 350 p; abundant smaller meshes, and larger ones up to 500 p diameter common. In places, 
both in the interior and on the surface, the meshwork becomes much closer, meshes here having 
diameter of about 100 p or even less; fibers a thickness of 10 to 20 p. On surfaces of attachment this 
fine network may form a continuous coating (diteliform veil). Sponge spicules are abundant in the 
dermal membrane and in the membrane lining the vestibular spaces. 
Main fibers are variable in abundance. In particular parts of the sponge they may be abundant, 
about 1 mm. apart, but in general they are sparsely scattered, interval between them being about 5 to 
6 mm. They extend, branching acutely as they go, from the attached surface, or simply from the 
interior out to the dermal surface, meeting the latter often very obliquely. Main fibers are frequently 
so curved that through a part of their course they lie tangentially in the walls of the vestibular spaces 
(course of the fibers is best seen in macerated and dried skeletons). They are cored with sand grains 
and sponge spicules; may be simple and about 60 ju in thickness, or double that thickness, and with 
irregular perforations so as to be fascicular. 
Genus CACOSPONGIA 0. Schmidt (1862). 
Meshes of skeletal network large, many easily distinguishable with unassisted eye. Main and 
connecting fibers clearly differentiated. Dried skeleton less elastic and more brittle than in Empong'ta ; 
some of the fibers, at any rate, thick as compared with Euspongia. 
Cacospongia spongeliformis, n. sp. 
Station 6072, one specimen; station 6079, one specimen. 
Sponge body cylindrical, somewhat branching. Diameter 5 to 7 mm.; larger specimen 250 mm. 
long. Sponge solid; with evident subdermal cavities between outer ends of radiating main fibers. 
Surface covered with small conical conuli about 0.5 mm. high, and 1 to 2 mm. apart; in places arranged 
so as to produce vaguely marked longitudinal ridges. Small oscula, 1 to 2 mm. diameter, distributed 
sparsely over surface. Flagellated chambers about 36 by 32 ju, with distinct canaliculi leading into the 
efferent canals, quite like those of Cacospongia scalaris as figured by Schulze (1879u, Taf. xxxvii, fig. 12) . 
Consistency rather yielding; rigidity scarcely great enough for the slender sponge body to stand erect. 
Color: one specimen dull lilac, color faded out in spots; other specimen colorless. 
Skeleton. — There are main longitudinal fibers 80 to 120 p thick, and from 500 to 1,000 p apart, 
packed thickly with sand grains and some spicule fragments; acutely forking, branches terminating in 
the conuli. Secondary fibers extending between main fibers, and between their branches, have a 
diameter commonly between 20 and 40 p; mostly without, or with very few foreign inclusions, although 
the larger ones are pretty abundantly cored with inclusions (sand grains, spicule fragments). Sec- 
ondary fibers join main fibers in some cases by an expanded base; in others by such a base with one 
or more perforations; in others again, the perforations are large enough to divide the base into two or 
three distinct roots. Many of the secondary fibers simple, passing undivided from main fiber to 
main fiber; others branch, forming coarse, irregular networks, with a mesh frequently about 400 p 
diameter, variation in general being 250 to 850 p. 
In the dermal membrane are many broken and entire foreign spicules, also sand grains and fora- 
minifer shells. Conuli round termination of main fibers particularly full of broken spicules. A com- 
mensal alga, apparently identical with the form Oscillana spongelix, discovered by Schulze i nSpongelia 
pallescens (Schulze, 18796, p. 147; Taf. vm, figs. 9, 10), is abundant throughout the body, although most 
abundant in the peripheral region. 
The species in habitus resembles Spongelia elegans Nardo (Schmidt, 1862, p. 28; Taf. hi, fig. 5). 
Its skeleton is very similar to that of Cacospongia vesiculifera Polejaeff (Polejaeff, 1884, p. 59; pi. iv, 
fig. 2; pi. vi, fig. 9) ; and this, as Polejaeff has pointed out, is essentially Spongelia-Uke. The peculiar 
cortical cells present in C. vesiculifera are absent in the Porto Rico form. 
