168 
Genus Stephanometra A. H. Clark. 
Stephanometra 1909. A. H. Clark, Proec. Biol. Soc. Wash., Vol. 22, p. 9. 
Stephanometra monacantha (Hartlau b). 
Antedon zebrinus Luitken, M., S. 
Antedon monacantha 1890. Hartlaub, Nachr. Ges. Gåttingen, Mai, 
1890, p. 179. 
Stephanometra monacantha 1909. A. H. Clark, Proc. Biol. Soc. Wash., 
Vol. 22, p. 1 
Nicobar Islands. One specimen with exactly twenty arms 
105 mm. long, the delicate and feathery distal portions of which 
is remarkably well preserved. The cirri are XXI, 18—19, 15 mm. 
—17 mm. long; first cirrus joint short, the following increasing in 
length to the fourth, which is squarish, then about half as long 
again as broad, becoming about as long as broad after the tenth; 
no dorsal spines: opposing spine present, though small, terminally 
situated, directed obliquely forward; terminal claw longer than the 
penultimate joint, slender, moderately curved. The. long lower 
joints of the cirri are somewhat ””dice-box shaped” as described 
by Hartlaub. 
P, small, 7.mm. long, with about eighteen joints; P, much 
enlarged, stiff and spine-like, 12 mm. long, with fourteen joints; 
P, only 5 mm. long. 
Tonga Islands. To this species I refer provisionally åa 
specimen from Tonga. It has twenty-eight arms about 60 mm. 
long, IIIBr series being developed exteriorly in 2, 1, 1, 2 order. 
The cirri are XXIII, 16—20 (usually 19), 10 mm. to 15 mm. 
long. P, is about 10 mm. long, stiff like P,, but more slender, 
with about fourteen joints, the first two squarish, the next half 
again as long as broad, the remainder two and one half to three 
times as long as wide; P, is 12 mm. long with ten to twelve 
joints, the first squarish, the third twice as long as broad, the 
following three times as long as broad; P, is not much more than 
one-half as long as P,, slender, slightly stiffened, with nine or 
ten joints; P, and the following pinnules are 4 mm. long, slender 
