108 MARINE INVERTEBRATES 
and one or more large oscula occur on top. The color of the living 
sponge is black. (Plates XX XIX, XL.) : 
E. officinalis, variety adriatica. More or less globose; sometimes 
attached by a broad base, sometimes by a short stem; latter form more 
or less club-shaped; oscula scattered over upper surface. Found in 
the West Indies and the Mediterranean. (Plate XL.) 
E. officinalis, variety motlissima, the Levant toilet-sponge. Gener- 
ally cup-shaped; oscula on inner side of cup or on upper flat surface ; 
very soft and elastic. 
E. officinalis, variety rotunda. Usually massive; attached by a 
broad base; sides vertical; oscula large and conspicuous on top, or 
small in longitudinal rows on the sides. In the young this variety may 
have a conical form with only one orifice, but later it has several oscula. 
Its rotundity of form increases with the number of large orifices, but in 
the adult stages the form varies, some being conical, while others have 
the top divided into radiating ridges. 
E. officinalis, variety dura. Irregular, massive, horizontally ex- 
panded, with conical process on upper surface. 
Genus Hippospongia 
HH. equina. Some of the sponges of this species are massive, spheri- 
eal, and attached by a small base; others are horizontally expanded or 
cake-shaped ; some have a depression in the upper surface and become 
cup-shaped. 
AI. equina, variety cerebriformis. Massive, circular, cake-shaped, 
often depressed in the center, producing a cup-shape, attached by broad 
-base; surface broken up by parallel longitudinal ridges having many 
tufts. Cup-shaped forms predominate, and have a more or less rough 
surface. This is one of the species known as grass-sponges. 
HI. equina, variety meandriformis, the velvet sponge. The sur- 
face of this variety has a protruding flattened cushion of fiber which. 
slightly resembles the convolutions of the brain-coral. Sometimes these 
cushions are extended into long pencils. The oscula are large and 
ragged on the edges; the shape is irregular. The average size is seven 
to eight inches in diameter. (Plate XL.) 
Hi. equina, variety elastica (variety agaricina, Hyatt), the yellow 
sponge. This is the second grade of commercial sponge, corresponding 
to the Zimocea sponge of the Mediterranean. It is found growing with 
the ‘‘ sheepswool” in a depth of two to twenty feet, and is abundant. 
It is massive and cake-shaped. The whole surface is a network covered 
with numerous small, fine cones. (Plate XL.) 
The variety dura is classed with this species, which it resembles in 
appearance, though it is harder in texture. 
HH. canaliculata. Massive, frondose; more or less horizontally 
expanded; bears finger-like processes of varying development on the 
upper surface. 
Ai. canaliculata, variety gossypina, the sheepswool sponge. Thisis 
the highest grade of the commercial bath-sponge. It is called “‘sheeps- 
wool” because, perhaps, of its irregular shaggy surface. It is covered 
with tufts, the larger oscula occupying the intervening depressions. 
