402 
BULLETIN OE THE UNITED STATES FISH COMMISSION. 
Euspong-ia officinalis (Linnaeus) var. rotunda Lendenfeld. 
Euspongia officinalis var. rotunda , Lendenfeld, 1889, p. 269. 
Ensenada Honda, Culebra, two small, flattened, massive specimens; station (?) , one somewhat 
larger, elongated, massive specimen 80 mm. high, waterworn. Upper surface covered with minute 
sharp-pointed conuli, which disappear on the sides as the edge of attached under surface is reached. 
Color of upper surface blackish, fading away on the sides into livid. 
Skeleton. — Main fibers have a diameter commonly between 40 and 60 /<, occasionally widening in 
spots; about 800 ju apart; abundantly cored with spicule fragments, rarely with sand grains. Secondary 
fibers measure, for the most part about 20 p diameter. Mesh is polygonal, frequently five-sided, with 
both rounded and angular corners, diameter commonly in neighborhood of 200 ju, but varying 
considerably. 
The distinctive features of the numerous varieties of the “bath sponge” are of such a vague 
intangible character, that I refer the Porto Rico specimens to a particular variety with considerable 
hesitation. 
Genus HIPPOSPONGIA F. E. Schulze (1879). 
Sponges with fine skeletal fibers, forming a network with comparatively small meshes, 0.1 to 
0.5 mm.; in the network thicker main fibers may or may not be distinguishable. Body permeated by 
a system of large canals (vestibular spaces), the intervening sponge tissue appearing as septa between 
the canals. 
Hippospongia intestinalis (Lamarck) Ridley. 
Spongiaintestinalis , Lamarck, 1813, p.434. 
Spongdia velata, Hyatt, 1877, p. 534, pi. xvii, fig. 8. 
Hippospongia intestinalis, var. Ridley, 1884, p. 590, pi. mi, fig. D. 
Station 6079, five specimens. 
Ridley (1. c. ) says: “The tortuous perforated tubes are sometimes single, but sometimes form 
confused reticulate masses; * * * their diameter varies from about 5 to 20 mm.” The Porto Rico 
forms differ from Ridley’s and Lamarck’s in the great scantiness of main sand-cored fibers. As to 
the relationship between my specimens and the skeletons described by Carter (1881, p. 366), under the 
name of Ilircinia clathrata, 1 am unable to reach an opinion. Ridley regards Carter’s species as a 
variety of Hippospongia intestinalis. 
Sponge body in four specimens divided into two or three elongate lobes, extending out from the 
central body, which is insignificant, appearing merely as a fusion of the lobes. Lobes which may 
branch are in general free from the substratum, mostly subrepent, though in some cases ascending; 
irregularly cylindrical, rounded at the end, with length of about 30 to 50 mm., and diameter of about 
20 to 30 mm. Lobes may be incrusting, in which case they become flattened, attached surface taking 
shape of substratum. The fifth specimen has a slender, somewhat tortuous, subcylindrical body, 
30 mm. long by 8 mm. wide, attached by entire under surface to a Ilircinia variabilis. 
Surface, which is much incrusted, especially with polyzoa, is for the most part smooth, though 
areas of very small sharp conuli are found here and there. Color of surface varies from nearly black 
to livid purple; light-brown inside. 
Large vestibular spaces having the shape of irregularly cylindrical canals, 5 to 10 mm. diameter, 
extend longitudinally through the lobes and excavate the central body. Diameter of the spaces as a 
rule considerably exceeds the thickness of the sponge tissue lying between them. Spaces separated 
from the exterior by the dermal membrane alone, or by only a thin sheet of sponge tissue; connecting 
with exterior by numerous rounded or elongate apertures, 2 to 5 mm. diameter, which are apt to form 
groups. Such apertures (pseudoscula) are present both at the ends and over the surface of the lobes, 
being mere perforations of the dermal membrane, which in immediate neighborhood of aperture, or 
group of apertures, forms an especially smooth area, usually, but not always, depressed below the 
general surface. Such areas are sometimes seen unperforated. 
The lining of the vestibular spaces is smooth only where the wall consists of thin membrane. It 
is for the most part roughened by minute and irregularly intersecting ridges produced into excessively 
minute conuli. Ridges are supported by the most superficial, tangentially lying, skeletal fibers (ridges, 
conuli, and fibers must be examined with a lens). There are degrees in the roughening: in places, the 
ridges are comparatively far apart, with intervening smooth areas, and here the general surface becomes 
