84 CCELENTEEATA 



M. prolifera (Ellis and Solander) (Fig. 142). Bright-red spon.e^es 

 incrusting on stones, shells, etc., when young, rising in digitate masses 

 sometimes 15 cm. high: South Carolina to Cape Cod from low water 

 mark to 10 fathoms; veiy common in Long Island Sound. 



3. Stylotella* Lendenfeld. Erect, incrusting sponges with very 

 little spongin and with needles in bundles; no microscleres; texture soft, 

 no hard rind present. 



S. heliophila H. V. Wilson (Fig. 143). Yellowish sponges, either 

 massive or with erect finger-like processes, 5 to 10 em. long and 5 cm. 

 high : common on stones and shells in shallow water. North Carolina. 



Order S. CERAOSPONGIAE. 



Sponges in which the skeleton consists of a close network of spongin 

 fibres without proper spicules : 4 families and about 40 genera, which are 

 found in tropical and subtropical seas. 



Family 1. SPONGIIBAE. 



Commercial sponges, f Spongin fibres solid, with a slender axial 

 core and frequently enclosing foreign bodies, such as sand; flagellate 

 chambers small with special openings by canalieuli into exhalent cavities: 

 7 genera and about 20 species, the fibrous skeleton of many of which is 

 used for commercial purposes. 



1. EusPONGiA Bronn. Body massive with slender spongin fibres 

 and very small meshes; simple main fibres usually containing sand, the 

 finer connecting fibres without sand : about 12 species ; cosmopolitan. 



E. officinalis (L.). Levant sponges. Fibres very elastic; form usu- 

 ally more or less globose, often lobed, cup-shaped or lamelliform; color 

 in life dark brown, being lighter beneath and on the sides: eastern Medi- 

 terranean; Bahamas; West Indies; Australia; in 1 to 100 fathoms; 

 several varieties are known, of which the most valuable is the light yel- 

 low cup-shaped E. mollissima from Asia Minor. The American variety, 

 the so-called glove sponge, is one of the least valuable commercial 

 sponges. 



2. HiPPOSPONGiA Schulze. Horse sponges. Body massive and per- 

 meated by large, often cavernous canals; fibres delicate and forming 

 an irregular network: about 20 species. 



* See "The Reactions of Sponges," etc., by G, H. Parker, Jonr. Exper. Zool., Vol. 

 8, p. 1, 1910. 



t See "Revision of North American Poriferae, Pt. I and II," by A. Hyatt, Mom. 

 Bost Soc. Nat. ITist., Vol. 2, 1875 and 1S77. "The Sponge Fishery and Trade," by 

 R. Rathbun, U. S. Com. of Fish., Sect. 5, Vol. 2, p. S17, 1887. "The Commercial Sponges 

 of Florida," by II. M. Smith, Bull. V. S. Fish. Com., Vol. 17, p. 22.5, 1897. "The 

 Commercial Sponges and Sponge Fisheries," by H. F. Moore, Bull. Bur. Fish., Vol. 28, 

 p. 403, 1910. 



