SPONGES COLLECTED IN PORTO RICO. 
409 
lamellae themselves rather vaguely developed (as compared with A. fenestrata), owing to fact that the 
meshes are not uniform in size, often irregular and large; diameter of mesh frequently 2 mm., or even 
larger. Skeletal fiber light brown to dark reddish-brown, fragile; 100 to 250 p thick; core, 0.8 to 0.9 
whole thickness. Sand grains and foreign spicules scattered in parenchyma, especially in basal part. 
Aplysina hirsuta (Hyatt) Lendenfeld. 
Verongia hirsuta, Hyatt, 1875, p. 403. 
Verongia hirsuta , Pol<§jaeff, 1884, p. 70, pi. 10, figs. 1, 2, 3. 
Aplysina hirsuta, Lendenfeld, 1889, p. 415. 
Station 6079, one specimen, 
Sponge consists of two cylindrical tubes, 40 mm. and 60 mm., respectively, in diameter, fused 
throughout their course so as to produce a roughly cylindrical, somewhat flattened mass, 320 by 
100 mm. Basal surface of mass flat, slightly smaller than the likewise flattened upper end. A very 
large osculum, narrowed in one diameter, at upper end of each tube. * Small oscula, 2 to 3 mm. 
diameter, abundant on lateral walls. Thickness of tube wall fairly uniform, about 12 mm. 
Sponge rather fleshy and compressible. Surface very uneven, elevated here, depressed there; 
marked by sharp, more or less meandering ridges, or by separate conuli, both about 1 mm. high. 
Intervening, smooth, depressed areas, 2 to 3 mm. wide, may be polygonal, or may not be so definitely 
circumscribed, in which case they appear as vaguely marked furrows. 
Skeleton . — Skeleton a uniform reticulum. Fiber about 100 p diameter; pith one-third whole thick- 
ness. Mesh polygonal or irregular, 1.5 to 3 mm. wide. Skeletal fibers, protruding from the conuli 
and surface ridges, unite to form an extra-superficial network, having an average thickness of 5 mm., 
in places twice that thickness. Beneath this network the dermal membrane is intact. A similar but 
much thinner extra-superficial growth is found, in patches, on inner walls of the tubes. Macerated 
skeleton very compi-essible; loose. 
Yon Lendenfeld says “sponge rose color. The skeleton is dark brown.” The Porto Rico speci- 
men is purplish, showing a lighter olive tint in the hollows. Color of fiber in the interior is a bright 
amber; extra-superficial fiber is light brown. 
Genus DENDROSPONGIA Hyatt (1875). 
Skeleton composed of dendritic fibers, which may anastomose to a slight extent, but do not form 
a. reticulum, as in Aplysina. 
Dendrospongia crassa Hyatt. 
Dendrospongia crassa, Hyatt, 1875, p. 401, pi. 13, figs. 1, 2, 7. 
Aplysina crassa, Lendenfeld, 1889, p. 423, pi. 35, fig. 3, pi. 38, fig. 7. 
Station 6079, three specimens; station ?, one specimen. 
Sponge irregularly lobate, lobes massive; in some cases attached to coral, then passing at the base 
into incrusting condition. Porto Rico specimens have greatest length of 100 to 120mm. Surface cov- 
ered with low, sharp conuli, often about 5 mm. apart; skeletal fibers frequently projecting from conuli. 
Color: Surface dark violet, almost black; interior dark violet, appearing reddish in sections. 
Dermal membrane over nearly entire surface, smooth, shining, and without pores. Here and 
there are tracts in which surface is reticulate. Reticulate appearance is caused by a network of low, flat, 
solid ridges about 140 p wide, which inclose depressed pore areas about 260 by 160 /f. Pores of each 
area considerable in number (15 in a typical case), 12 to 20 p in diameter, opening into subdermal 
cavities. In spots the reticulate condition of surface is distinct, but the pores are absent. In other 
places the reticulate condition is imperfectly developed. The varying character of the surface suggests 
that not only do the pores appear and disappear, but that with them possibly comes and goes the 
reticulate arrangement. Minute apertures (oscula?), about 0.5 mm. diameter, scattered over surface 
in some abundance. An occasional osculum, 2 to 3 mm. diameter, is also found. 
Ectosome densely crowded with spindle-shaped cells; light in color. Similar tissue extends into 
interior, especially abundant round larger canals. Subdermal cavities are found here and there, but in 
general their place is taken by small canals in the ectosome. Flagellated chambers in one of my 
specimens measures 32 by 24 ju. 
Skeleton . — The dendritic fibers composing the skeleton may anastomose to some extent, without, 
however, producing a reticulum; although an occasional squarish mesh, about 2 mm- diameter, may 
