THE GRASS AND YELLOW SPONGES. 849 



the connecting or secondary fibers are composed of pure keratose. The surface is also remarkable 

 for the protruding, flattened cushions of fiber, which slightly resemble the convoluted ridges 

 of a meanclrina. Sometimes these cushions are transformed into long, solid brushes or pencils of 

 fibers." 



The localities from which this subspecies has been recorded are as follows : Biscayne Bay and 

 Key West, Florida; Nassau, Bahamas; Havana, Cuba; Mauritius Islands; and the island of 

 Fernando de Noronha, oft" the coast of Brazil. But one variety of this subspecies has been recog- 

 nized ; it is also in its typical form known commercially as the Velvet Sponge. Professor Hyatt 

 writes of it as follows : " The forms of the specimens in our collection are more spreading than is 

 usual in that variety {mean'driniformis), and the texture is quite as soft, though denser, perhaps, 

 when the skeleton is dry. The projecting cushions of fiber are similar in form to those of variety 

 meandriniformis, but are joined together in larger masses by a tissue of fine superficial threads ; also 

 are often less dense and simply bridge the intermediate channels. This and the tortuous and 

 rather shallow character of the channels give the surface a smoother aspect than is common in the 

 skeleton of meandriniforntis. The oscules are very large and have a peculiar ragged aspect in dried 

 specimens. They look as if some one had made them by repeatedly running a knifejnto the animal 

 while it was drying, and then omitted to clean out the interior thoroughly, leaving sharp pinnacles 

 of dried sponge cuttings projecting inward, sometimes so as to fill the center, but oftener sticking 

 around the center of the aperture, and more or less completely joined to the wall of the canal. 

 This characteristic ragged look is sometimes also to be seen in the oscules of subspecies gossypina. 

 but never so decidedly." This variety is found at Key West, Florida, and Nassau, Bahamas. 



This is a fair grade of Sponge, rather rare, and not much in demand ; in fact, the dealers 

 often omit it in their enumeration of the American commercial Sponges. It is considered of little 

 value by the trade. 



The Grass Sponge — Spongia equina, Schm., subspecies OBEEBErpoRMis. 



" The aspect of this species, commonly known as one of the ' Grass Sponges,' is very similar to 

 that of Spongia agaricina, subspecies corlosia, variety typica. The diffierence consists principally 

 in the aspect of the surface. This is broken up by parallel longitudinal ridges of irregular length 

 on the sides, each ornamented with one or two lines of tufts. These ridges extend onto the upper 

 surface, giving them a markedly radiatory arrangement. The larger orifices are situated in rows 

 in the channels between the ridges." Six varieties are enumerated, as follows : typica, described 

 above; jjZfflwa, inhabiting Florida and Kingsmill's Islands; divisa, fonnd upon hard, irregular bottom 

 or corals, in about two feet of water at low tide, at Key West and Biscayne Bay, Florida, and at 

 Stone's Inlet, South Carolina; mexicana, from Vera Cruz, Mexico; caliciformis, from Nassau, 

 Bahamas; and obscura, from Nassau and the Bermudas. These several varieties differ more or 

 ■less markedly from the typical specimens, some of them approaching other species in shape and 

 general appearance. This grade is inferior in quality. 



The Yellow Sponge — Spongia agaricina, Pall., subspecies corlosia and dura. 



" The subspecies corlosia resembles very closely in external appearance the Spongia dura, or 

 'Hard Head,' but an examination of a full series of forms showed that very considerable differ- 

 ences exist in the texture, though superficially there is little or no distinction in the aspect of the 

 surface. Dealers can identify these varieties instantly by the color, which is usually lighter than 

 that of the 'Hard Head,' and by the touch, the 'Yellow Sponge' yielding much more readily and 

 feeling less harsh under the fingers. These characters, however, only apply to the normal head- 

 like forms and some of the varieties; many forms cannot be placed in either one or the other of 

 54 p 



