217 
the relative proportions of the lower pinnules, by some curious accident, were wrongly described. 
P, is 3.2 mm. lono^ with 10-11 segments; P., is 6 mm. long with i;, — 14 segments, propor- 
tionately stouter than 1',; P., is 9 mm. to 10 mm. long with 17 — 19 segments, the lartrest 
pinnule on the ami; 1\ is 4.5 mm. long with 13 segments; P. is 4.5 mm. long with 12 seg- 
ments, slightly stouter than P^ and bearing a genital gland. The cirri are about XXXV, 13 — 15, 
10 mm. long; the longest segments (the third and fourth) are twice as long as the diameter 
of the expanded ends; the last two before the penultimate are only slightly longer than broad. 
The arms are 60 mm. long. 
6. Dorometra aegyptica (A. H. Clark). 
A. H ("l.-vkk. l^roc. U.S. National .Museum, vol. 40, 1911, p. 42 (Iridometfa aegyptica). 
Smithsonian Miscellaneous Collections, vol. 61, 1913, N" 15, p. 53 (Iridoinetra aegyptica). 
7. Dorometra clyinene nov. sp. 
Stat. 167. 2°35'.5S., i3i°26'.2E. Ceram Sea. 95 Metres, i E>v. 
The cirri are e.xceedingly .slender, 9 mm. long, composed of 11 — 12 segments of which 
the longer proximal are about four times as long as the diameter of the much e.xpanded 
distal ends and the penultimate is twice as long as broad ; the opposing spine is indicated 
bv a verv minute tubercle, or is absent altogether; the terminal claw is very slender, and only 
slightly curved. 
The arms are 40 mm. long, and resemble those of the other species of the genus. 
P, is 2 mm. long with 8 segments. P„ is 3.5 mm. long with 8 — 9 segments. P., is 
4.5 mm. long with 9 segments. P^ is shorter and smaller than P.j. 
Hybometra A. H. Clark. 
The only species in the genus Hybo7netra is 
I. Hybotnetra senta A. H. Clark. 
A. H. Cl.-vkk. Smithsonian Miscellaneous Collections, vol. 61, 1913, N" 15, p- 54 (Hybometra 
senta). 
2'"' Subfamily Th y sanometri n ae A. H. Clark. 
Key to the Genera of the Subfamily Thysanometrinae. 
a' P, with the third segment as long as, or longer than, broad, and the fol- 
lowing segments markedly longer than broad (southern Japan and the 
'Admiralty Islands; 126—355 Metres) Thysanometra 
a- Pj with the third segment broader than long, and the fourth broader than 
long, or about as long as broad (Caribbean Sea, and northward to 
North Carolina; 13—1029 Metres) Coccometra 
SIBOGA-EXPEDITIE Xl.II/i. *° 
