15' 
b^ 28 arms: stout aiul robust, with large stout cirri which are more than half 
the length of tlie arms (Lesser S u n d a Islands; 204 Metres). . . magna 
b'- 13 — 22 (usually 20) arms; slender, with slender cirri which are considerably 
less than half the length of the arms (Malay Archipelago and the 
Philippine Islands; 54 — 502 Metres) antiandalei 
1. Occaiiouicira (^iganiea (A. H. Clark). 
A. H. Clakk. Proc. U.S. National Museum, vol. 34, 1908, p. 222 (Thalassoiitetra gigantea). 
2. Oceanometra magna (A. H. Clark). 
A. H. Cl.\kk. Zool. Anzciger, vol. 39, 1912, N" n 12, p. 425 [Thalassometra magna). 
Stat. 251. 5'^28'.4S., 132° o. 2 E. Arafura Sea. 204 Metres, i Ex. 
The centrodorsal is conical, the sides slightly swollen, the tip truncated, 5.5 mm. broad 
at the base and 5 mm. high; the dorsal pole is about 1.5 mm. in diameter, approximately 
flat, covered with fine papillae; the cirrus sockets are arranged in ten columns, two to each 
radial area, usually four (rarely three or five) to a column; on the outer side of each radial 
area the columns are closely crowded against the columns of adjacent radial areas, but in the 
midradial line they are separated by a bare, slightly concave, area which proximally is nearly 
or quite as broad as the adjacent cirrus sockets, but which rapidly becomes narrow so that 
the outermost one or two sockets in each area are in contact in the midradial line. Very deep, 
though very narrow, subradial clefts separate the centrodor.sal from the radials. 
The cirri are XXX — XL, 66 — 74, 70 mm. to 85 mm. long; the shorter cirri toward 
the apex of the centrodorsal are 60 mm. long with 59 .segments. The first cirrus segment is 
very short, and the following slowly increase in length to the fifth, which is slightly more than 
twice as broad as long, and the seventh, which is about as long as broad; the eighth is a 
transition segment, nearly or quite twice as long as the distal diameter; the ninth is similar; 
the following slowly decrease in length to the twenty-second or twenty-third, which is about as 
long as its proximal diameter, and still further to those in the di.stal fifth of the cirri, which are 
twice as broad as lonsf, and the terminal, which are still shorter. On the fifteenth or sixteenth 
the distal dorsal edge begins to project in the median line; on the succeeding segments this 
projection slowly increases in extent and, the middorsal line of the segments rising into a sharp 
keel, transforms on the short distal segments into the very high carinate dorsal spines charact- 
eristic of the genus. The last six or seven segments gradually decrease in diameter so that 
the penultimate segment is very small. The distal edges of the earlier segments, especially 
dorsally, are very finely spinous so that the cirri are rough to the touch. 
The ends of the basal rays are visible as dorsoventrally elongate tubercles bridging over 
the subradial clefts. 
The radials are very short, with a slight rounded median prominence and with a lew 
small teeth on the distal margin. The IBrj are short, between four and five times as broad as 
