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THE VOYAGE OF H.M.S. CHALLENGER. 
Ecionema nigrum, n. sp. 
Sponge. — Massive, lobate, ridged ; surface even. 
Spicules. — I. Megascleres. 1. Oxea, fusiform, frequently bent at the middle, 
sharply pointed, 2'4 by 0‘058 mm. 
2. Plagiotrisene, rhabdome conical, sharply pointed, 2*86 by 0*058 mm., cladi 
0*27 mm. long. 
3. Anatrisene, rhabdome cylindrical, sharply pointed or strongylate, 3*18 by 
0*015 mm., cladi 0*0516 mm., chord 0*0775 mm., sagitta 0*039 mm. long. 
II. Microscleres. 4. Microstrongyle, fusiform, centrotylote, smooth or roughened, 
0*001 mm. long. 
5. Chiaster, slender, terminally tylote actines, 0*016 mm. in diameter. 
Colour . — Surface black, interior greyish. 
Habitat. — West Coast of Africa ; a fragment of this sponge was given me by Professor 
Stewart for description from the collection of the Eoyal College of Surgeons, London. 
Ecionema rotundum, n. n. 
Ecionema acervus, Ridley, Spong. “Alert,” p. 627, 1884 (wore Bowerbank). 
Sponge. — Ovate, free. 
Spicules. — I. Megascleres. 1. Oxea, stout, fusiform, bent, somewhat abruptly 
pointed, 2*1 by 0*059 mm. 2. Plagiotrisene, rhabdome conical, 1*6 by 0*05 mm., cladi 
0*2 mm. in length. 3. Anatrisene, rhabdome 20 by 0*013 mm., cladi 0*058 mm.; 
cladome flattened in front, cladi 0*128 mm., chord 0*128 mm., sagitta 0*0954 mm. in 
length. • 
II. Microscleres. 4. Microstrongyle, fusiform, sometimes faintly centrotylote, surface 
minutely roughened, 0*016 mm. in length. 5. Chiaster, centrum absent, actines slender, 
bacillary, terminally tylote, 0*012 mm. in total diameter. 
Habitat. — Etoile, Amirante Group ; depth, 13 fathoms. 
Remarhs. — The distinction of this species from Ecionema acervus, Bwk., depends on 
the size of the spicules, the megascleres in Bowerbank’s species being considerably larger 
than those in Eidley’s. 
. Genus 16. Papyrula, 0. Schmidt. 
Papyrula, Oscar Schmidt, Spong. Adriat. Meeres, Suppl., iv. p. 18, 1868. 
Ehabdasterose Stellettidse in which one of the microscleres is a microrabd 
(microxea), the other an aster. The microxeas are scattered through the choanosome, 
and densely crowded in the thin ectosome. 
