140 BULLETIN OF THE BUREAU OF FISHERIES. 
Skeletal framework.—The skeleton of the choanosome (Pl. LVI, fig. 1) consists of irregularly scattered 
megascleres, together with loose spicule tracts. Collections of sand grains occur abundantly in the choano- 
some. ‘There isa cortical layer 1 to 1.5 millimeters in thickness, composed of compactly and confusedly 
arranged spicules, which however, in the main, point in a more or less radial direction, sometimes ex- 
tending beyond the surface. This cortex is pretty definitely marked off from the underlying choano- 
some, in which the spicules are not nearly so abundant. ‘There is no noticeable difference in the size 
of the spicules of the cortex and those of the choanosome. At the base of the cortex there is present in 
most places a thin layer of spicules arranged more or less parallel to the surface (Pl. LVI, fig. z). 
The canals are in general small, mostly 50 to 150 nin diameter, but some are 500 » or more in diameter. 
The sponge tissue is dense and granular. The flagellated chambers are inconspicuous and measure 
about 30 4 in diameter. 
This interesting sponge is evidently very close to the well-known ‘“‘Neptune’s Cup,” 
Poterion patera (Hardwicke), of the Pacific, which Vosmaer some years ago (1908) 
showed to belong in the Clionide. Topsent reviewing Vosmaer’s paper (1909) would 
delete Poterion, merging it into Cliona. But the final structure assumed is such a 
marked one that the genus should be retained, as Vosmaer more recently has held 
(1911, p. 3). 
Poterion patera, which is not uncommon in the Malay Archipelago, reaches a height 
of 1 meter, with an aperture of 30 centimeters, the wall of the cup 25 millimeters thick 
(Vosmaer, loc. cit.). The Beaufort sponge differs from the Pacific species in the larger 
size and closer grouping ofits poreareas. These (Vosmaer, loc. cit.) in the latter form are 
indistinct in outline, something over 1 millimeter in diameter, and about the same dis- 
tance apart. The internal skeleton is stronger in the Pacific species than in the Beaufort 
form, consisting in the former of a firm trabecular network, the trabeculee made up of 
closely packed tylostyles and including in the axial region here and there a little spongin 
(Vosmaer). The spicules in P. patera range in size from 450 uw by 14 to 11 w to 200 
by 10 to 7m (Topsent, loc. cit.). 
Family SUBERITIDA. 
Megascleres tylostyles or styles. Microscleres absent or represented in some forms 
by centrotylote microstrongyles. 
Suberites Nardo. 
Body frequently massive, but it may branch or become covered with outgrowing 
lobes. Without mammiform papille. Megascleres nearly always tylostyles. No 
microscleres. The spicules diminish in size toward the surface. The superficial spicules 
project radially, and the skeleton, as a whole, may exhibit in some measure a radiate 
arrangement. 
Suberites undulatus, n.sp. (Pl. LVII, figs. 8, 9, 10, 11; Pl. LXVI, fig. 52.) 
Fairly common in the muddy pools left at low tide around “Green Rock,’’ in Newport River. 
Sponge (Pl. LVII, fig. 8), a speroidal mass, made up of a basal undivided portion and closely set lamel- 
late and narrow, ascending lobes into which the former is produced over its superior and lateral surfaces. 
A characteristic specimen (the type) measures 60 millimeters in height, with transverse diameters of 
75 and go millimeters. It was attached below to the shells of live oysters. A few pieces of shell were 
incorporated in its basal portion, end some alge grew out from between the lower lobes. 
Color light gray. Sponge fairly firm; compressible and easily torn. 
The lamellate lobes are all more or less radial, but flattened in various planes. They are thus 
inclined to one another at all angles. Where they meet they are apt to fuse; this produces cavities 
closed below and around the sides, which extend into the sponge interior and open above between the 
