418 BULLETIN OF THE BUREAU OF FISHERIES. 
which obscure the oscula and produce a cavernous interior. The walls in this 
type of sponge tend to become more vertical and the base of attachment broader, 
and as the top is often concave by the decay of the tissues, the sponge is more 
like the Anclote sponges, from which it is distinguished by its more irregular 
surface, its cavernous interior, thicker rim, and greater compressibility and 
tenderness of fiber, as well as by the presence of oscula on the outer surface. In 
other specimens the outer walls are smoother, with fewer and less conspicuous 
oscula, and the tufts of fibers are shorter and more uniform, exhibiting between 
them numerous small orifices. The whole top of these specimens, excepting a 
zone at the rim, is perforated by pores of uniform size, like those described in 
the first variety. ; 
The Key sponges appear to be Hyatt’s varieties typica, plana, divisa, and 
caliciformis, although his descriptions can not be recognized with certainty. 
The gradations are multifarious. 
Bahama grass (pl. L11).—These differ strongly in general appearance from 
the Anclote and Key sponges and most of them probably, though by no means 
certainly, belong to Hyatt’s variety obscura. They are generally round or 
cake-shaped and regular and are covered with fibrous tufts and pencils some- 
what resembling those of the sheepswool sponge. ‘The oscula are rather numer- 
ous, circular, and confined mainly, though not entirely, to the upper surface; 
but each has its own tube separated from that of its fellows, and there is nothing 
resembling the sieve-like upper surface of the Key sponges. The oscular tubes 
are thin-walled, of nearly uniform length in each individual, and the spaces 
between them are more or less completely filled with an irregular net or loose 
felt of fibers. In older specimens the soft superficial tufts often almost or quite 
disappear and the walls of the tubes break down, producing a rough, ragged 
exterior. The small specimens are light yellow, soft and compressible, the 
larger ones brown, harsh, elastic, stiff, and weaker in texture. Specimens from 
Andros Island, which grow principally on sea feathers, are nearly spherical, the 
oscula are less conspicuous, the surface tufts cushioned or palmate, and the 
texture weak. 
Cuba grass (pl. L11).—The Cuba grass sponges considered as a whole are 
intermediate between the Key and the Bahama sponges. In a given lot there 
are likely to be specimens resembling the plana type of Key sponges and others 
like the obscura type from the Bahamas with more or less intergradation. In 
old age the obscura type sometimes becomes cavernous and with a very irregular 
nodular surface. The quality on the whole is inferior to that of the same grade 
from the Bahamas. 
Honduras grass.—The grass sponges from British Honduras appear to 
belong to the obscura type and resemble the coarser and harsher of the Bahaman 
