80 U.S. NATIONAL MUSEUM BULLETIN 272 



Genus Ephydatia Lamouroux, 1816, redefined 



Spongia Linnaeiis, 1758, p. 1348 (part). 



Ephydatia Lamouroux, 1816, p. 2 (part). — Gray, 1867, p. 550 (part). — Vejdovsky, 

 1883b, p. 23; in Potts, 1887, p. 177.— Wierzejski, 1886, p. 205.— Weltner, 

 1895, p. 114.— Hauitsch, 1895a, p. 127.— Girod, 1899, p. 110.— Rousseau, 

 1906, p. 126.— Annandale, 1909b, p. 107; 1909e, p. 567; 1911c, p. 108; 1912d, 

 p. 384; 1918a, p. 212. — Annandale and Kawamura, 1916, p. 12. — Gee and 

 Wu, 1925c, p. 9; 1928, p. 3.— Gee, 1927c, p. 179; 1930b, p. 170; 1931e, p. 37; 

 1932c, p. 28.— Arndt, 1926, p. 342; 192Sa, p. 66.— De Laubenfels, 1932, 

 p. Ill; 1936, p. 37.— Jewell, 1952, p. 445. 



Halichondria Fleming, 1828, p. 524 (part). 



Spongilla Lamarck, 1816, p. 98 (part). — Johnston, 1842, p. 5. — Lieberkiihn, 

 1856, p. 510 (part).— Bowerbank, 1863, p. 445 (part).- Carter, 1868, p. 247 

 (part).— Vejdovsky, 1877, p. 213 (part) .—Dawson, 1878, p. 1 (part) .—Potts, 

 1880a, p. 357 (part). 



Tr achy spongilla Dybowsky, 1878, p. 53. — De Laubenfels, 1936, p. 37, 



Pleiomeyenia Mills, 1884, p. 147. 



Meyenia Carter, 188 la, p. 90 (part) .—Potts, 1887, p. 210 (part).— Has well, 1882, 

 p. 210.— Lendenfeld, 1887, p. 91.— MacKay, 1889, p. 92 (part).— Kirsch, 

 1909, p. 37.— De Laubenfels, 1936, p. 36.— Eshleman, 1950, p. 38.— Wurtz, 

 1952, p. 4.— Jewell, 1952, p. 445.— Penney, 1960, p. 46 (part). 



Type species. — By present selection Spongia fluviatilis Linnaeus, 

 1758. 



Definition. — Megascleres slender and fusiform to rather robust 

 and cylindrical amphioxea, entirely smooth or covered with a variable 

 number of spines, except at their tips. 



Microscleres absent. 



Gemmoscleres tj^pically birotulates of one length group in all 

 species wdth smooth megascleres; in those possessing spiny mega- 

 scleres often of varying lengths, but not representing two distinct 

 length groups; rotules of identical or only slightly differing outline, 

 always flat in lateral view; shafts either slender, smooth or incipiently 

 spined, or rather robust and covered with erect acute spines. 



Gemmules moderately large to large, subspherical to spherical, 

 scattered throughout skeletal meshwork, usually very abundant; 

 pneumatic layer well developed but of irregular thickness, consisting 

 of minute spherical to subspherical air spaces; gemmoscleres em- 

 bedded in this coat strictly radially, in one or more layers, their distal 

 rotules often clearly visible through outer gemmular membrane; 

 foramen a simple elevation, without a porus tube, usually surrounded 

 by a narrow peripheral collar. 



Sponges forming flat to massive encrustations, surface as a rule 

 distinctly corrugated; associations with zoochlorellae recorded for 

 some species. Consistency ranging from soft to moderately firm. 



Distribution of one species cosmopolitan, with preference to cold- 

 and warm-temperate climates; several species widely scattered 

 throughout the Northern Hemisphere, and absent from the tropics 



