86 U.S. NATIONAL MUSEUM BULLETIN 272 



Spongilla polymorpha Potts, 1880b, p. 357. 



Meyenia fluviatilis Carter, 1881a, p. 92 (part). — Potts, 1886, p. 228 (part); 

 1887, p. 219 (part).— MacKay, 1885, p. 233; 1889, p. 92. 



Meyenia acuminata Potts, 1882, p. 70. 



Ephydatia amphizona Vejdovsky, 1883a, p. 331. 



Ephydatia miilleri Vejdovsky, 1883b, p. 26.— Petr, 1886, p. 107.— Traxler, 1889, 

 p. 14.— Hanitsch, 1895a, p. 125.— Weltner, 1895, p. 114; 1909, p. 186.— 

 Levander, 1901, p. 56.— Ptousseau, 1906, p. 124.— Luhe, 1908, p. 311.— 

 Stephens, 1912, p. 8; 1920, p. 235.— Topsent, 1914, p. 538.— Smith, 1921, 

 p. 17; 1930, p. 184.— Arndt, 1923, p. 75; 1926, p. 342; 1928a, p. 68; 1931, 

 p. 37; 1932b, p. 304; 1933a, p. 19; 1938b, p. 76.— Poisson, 1923, p. 62; 1925, 

 p. 94.— Rezvoj, 1926b, p. 64; 1928a, p. 231; 1930, p. 183.— Gee, 1929b, p. 13; 

 1930d, p. 369; 1930b, p. 170; 1930e, p. 27; 1931d, p. 44; 1931b, p. 269; 1931a, 

 p. 502; 1932c, p. 30; 1932d, p. 54; 1937, p. 285.— Shroder, 1938a, p. 295.— 

 Jewell, 1935, p. 461; 1939, p. 16.— Karaman, 1935, p. 46.— Old, 1936b, 

 p. 11.— Zimmer, 1936, p. 126.— Sasaki, 1940, p. 183.— Simon, 1952, p. 80; 

 1953, p. 207. 



Spongilla mirabilis Retzer, 1883, p. 25 (part). — Schroder, 1926, p. 249. 



Ephydatia miilleri var. astrodiscus Vejdovsky, 1883b, p. 29. — Arndt, 1926, p. 343. 



Pleiomeyenia calumeticus Mills, 1884, p. 147. — Smith, 1921, p. 12. — Gee, 1931e, 

 p. 35. 



Pleiomeyenia walkeri Mills, 1884, p. 147. 



Pleiomeyenia spinifera Mills, 1884, p. 149. 



Meyenia asfrosperma Potts, 1887, p. 219. 



Meyenia polymorpha Potts, 1887, p. 219. 



Meyenia fluviatilis var. acuminata Potts, 1887, p. 219. 



Ephydatia olchonensis Swartschewsky, 1901, p. 9. — Annandale, 1918a, p. 213. — 

 Gee, 193 le, p. 45. 



Ephydatia miilleri var. fce/inmg'i Kirkpatrick, 1915, p. 104. — Arndt, 1926, p. 343. — 

 Gee, 1931e, p. 33. 



Ephydatia obtusosclera Kozhoff, 1925, p. 38. — Gee, 193 le, p. 45. 



Ephydatia sibirica Kozhoff, 1925, p. 29. — Gee, 1931e, p. 49. 



Ephydatia solida Kozhoff, 1925, p. 36. — Gee, 1931e, p. 49. 



Ephydatia miilleri var. acuminata Arndt, 1926, p. 343. — Rezvoj, 1928a, p. 231; 

 1929, p. 291.— Smith, 1930, p. 184. 



Ephydatia miilleri var. obtusosclera Kozhoff, 1930, p. 164. 



Ephydatia miilleri var. sibirica Kozhoff, 1930, p. 162. 



Ephydatia mvlleri var. solida Gee, 1932c, p. 30. 



Meyenia miilleri Old, 1932a, p. 132.— Wurtz, 1950, p. 4.— Pennak, 1953, p. 93.— 

 Penney, 1960, p. 51 (part). 



Material. — Extremely numerous specimens and slide material; 

 EUROPE: Sweden, Finland, Netherlands, Belgium, Switzerland, 

 Germany, Austria, Hungary, Czechoslovakia, Poland, U.S.S.E..; 

 NORTH AMERICA: U.S.A., Canada; ASIA: U.S.S.R., China, 

 Japan. 



Description. — Mature sponge variable in shape, ranging from 

 very thin films to moderately thick crusts; surface even in flat speci- 

 mens, forming rounded elevations in more massive growths, always 

 slightly hispid; oscula inconspicuous, dermal membrane well de- 

 veloped. Skeleton forming an irregular network of distinct vertical 



