408 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
Aplysina fenestrata Carter. 
Spongia fenestrata, Duchassaing ot Michelotti, 1804, p. 30, pi. hi, fig. 7. 
Aplysina fenestrata, Carter, 1882, p. 272. 
Station 6079, one specimen. 
Carter describes the species as “massive, sessile, lobate, hollow,” with “vents large, on the prom- 
inent parts of the body.” In the figure given by Duchassaing et Michelotti, the large apertures are 
represented on the apices of mammillary lobes. The Porto Rico specimen is an irregular mass, 150 
mm. long, with an average thickness of 50 mm., and apparently without a surface of attachment. 
It may have been held in place by a branching coral, or something of that sort. The mass is exca- 
vated by large concavities, some of which extend entirely through the body. It is thus imperfectly 
and very irregularly divided into lobes. At one end is a rounded aperture, 18 mm. diameter, leading 
into a cloaca-like depression 35 mm. deep, having a smooth inner wall. At the opposite end is a 
similar but smaller aperture, leading into a shallower depression. These apertures probably corre- 
spond to the “vents” of Carter’s specimens. Sponge body itself is solid, and with no discoverable 
true oscula. Color: surface black, purplish-brown where water-worn; interior, olive-brown. 
Surface is divided into polygonal concave areas, having an average diameter of about 5 mm. Such 
areas sometimes shallow, mostly deep; sometimes regularly 5 or 6 sided; again rounded or irregular, 
often owing to confluence. (Figure given by Duchassaing et Michelotti is schematic.) Dermal mem- 
brane lining concavities, shining. Where the concave areas are deep, the separating ridges become 
thin walls (as in the description of D. et M. ). From the sharp edges of the bounding ridges, skeletal 
fibers may protrude, occasionally to such an extent that the lamellar structure of the skeleton is 
shown. 
Dermal membrane over almost entire surface, quite smooth and without pores. Here and there 
a tract is found with a few pores, and in which the reticulate condition exhibited by the dermal mem- 
brane of many horny sponges {Aplysina fragilis for example) is imperfectly developed. 
Skeleton . — Skeletal fibers form strong reticulate lamellae, extending directly inward from bound- 
ing edges of the surface areas. These lamellae meet one another at about a right angle. Skeleton is 
thus given a honeycomb-like character; the outer open end of each “cell” of the honeycomb 
embracing one of the surface areas. In each lamella the meshes are squarish, or polygonal, and 1 to 
2 mm. diameter. Fiber about 200 p thick, of deep amber color; core 0.3 to 0.5 whole thickness, and 
distinct (indistinct, as given by Carter). Sand grains sparsely scattered in parenchyma. 
There seems to be no doubt that the Porto Rico specimen belongs to the same species as the 
sponges described by Carter under A. fenestrata. Von Lendenfeld, however (1889, p. 413), lists this 
species as a synonym of A. archeri, although the two are very different. 
Aplysina frag-ilis, n. sp. 
Station 6097, one specimen. 
Sponge incrusting on coral, becoming massive at one end. Greatest length, 80 mm.; thickness, 
5 to 15 mm. Color: surface dark violet, almost black; reddish violet inside. Low conuli in neighbor- 
hood of 1 mm. high, scattered over surface, usually 3 to 4 mm. apart, in places nearly disappearing. 
Surface reticulate except at extreme edge of specimen, where it is smooth. Reticulate character is 
caused by a network of low solid ridges, 85 to 170 p thick, including depressed areas about 1 mm. 
diameter, which are, however, more or less subdivided by lower and narrower ridges. In each 
depressed area there is a considerable number of pores, 12 to 30 p diameter, opening into subdermal 
cavities. No large oscula to be seen. A few small round apertures (oscula?), 0.5 mm. or less in 
diameter, are scattered over surface. 
Subdermal cavities numerous and fairly extensive. Canals of interior numerous and large. In 
outer layer of ectosome are crowded granular cells giving color to surface. Remaining ectosome 
lighter in color, containing numerous fine spindle or branched cells in a clear ground substance. A 
similar light-colored tissue is abundant round some of the larger canals. 
Skeleton . — Skeletal fibers form reticulate lamellae, lying vertical to surface and meeting one another 
about at right angles, so as to produce a honeycomb-like structure. From outer edge of lamellae single 
libers extend radially into conuli. Diameter of the “cell” formed by lamellae, about 4 mm. The 
