224 
a'- Centrodorsal shorter, not longer than broad, usually conical, sharply pointed 
with straight sides 
b' four columns of cirrus sockets in each radial area 
c' cirrus sockets very closely crowded against each other; the twentv columns 
of cirrus sockets are closely crowded all around the centrodorsal, excepting 
only where the downward extension of the basal rays separates the most 
proximal sockets of the outermost columns of each radial area (Hawaiian 
Islands; 720 — 900 Metres) congesta 
c' cirrus sockets widely separated from each other, arranged in four, with 
sometimes a partial fifth, columns in each radial area; narrow interradial 
lines divide the sides of the centrodorsal into five radial regions, tip of 
the centrodorsal truncated instead of sharply rounded as in the preceding 
(Galapagos Islands and Panama; 693 — 999 Metres) .... bigradata 
\r not more than three columns of cirrus sockets in each radial area 
c^ size large; arms probably between 130 mm. and 150 mm. long; centro- 
dorsal large, a broadly truncated cone, with three complete and equal, 
very closely placed, columns of four or five (usually four) cirrus sockets 
in each radial area ; relatively broad interradial lines, nearly as broad as 
the adjacent cirrus sockets, delimit the radial areas; Pj, though similar 
to the succeeding pinnules, is longer and slightly stouter basally ; the 
cirri are about 50 mm. long, composed of 35 — 40 segments (northern 
part of the Sea of Japan; 702 — 731 Metres) crythrizon 
c" smaller, the arms not over 100 m.m. long; centrodorsal a sharply pointed 
cone or a low hemisphere, never a broadly truncated cone ; cirrus sockets 
arranged in two columns in each radial area, or in two columns with a 
partial median column 
d^ cirrus sockets in two entire columns and one short and incomplete 
column in each radial area of the centrodorsal, the incomplete column 
between the two entire columns, which meet beyond it 
e^ larger, the centrodorsal being from 4 mm. to 5.5 mm. broad at the 
base and from 4 mm. to 3 mm. high, sharply conical; cirrus sockets 
very definite in arrangement, the interradial furrows very regular, 
broad, and well marked 
f the incomplete median column of cirrus sockets consists of two 
sockets, with occasionally a more or less developed third ; the 
radial areas are delimited by deep grooves which are about as 
wide as the adjacent cirrus sockets; the centrodorsal is 5.5 mm. 
broad at the base, and measures 5 mm. along the sides (A n- 
daman .Sea to the Postilion Islands, north of -Sum- 
bawa; 338 — 794 Metres) major 
{- the incomplete median column of cirrus sockets consists of a 
