230 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. XXXIV. 
Distal edges of radials even with the edge of the centro-dorsal, 
and very slightly curved, not extending up into the angles of the 
calyx interradially; first costals very short (six or eight times as 
broad as long) and bandlike, with a rounded notch in the distal 
median line; costal axillaries rhombic, about half again as broad as 
long, with a rounded posterior projection incising the first costals: 
the anterior sides are moderately concave, but the anterior angle is 
not especially long; costals and two lowest brachials in close appo- 
sition and laterally flattened. Ten arms 45 mm. to 60 mm. long 
(usually about 50 mm. to 55 mm.) ; first brachial very short, much 
longer outwardly than inwardly, and almost ‘bisected by a backward 
prolongation from the second brachial, which is irregular in shape 
and considerably larger; third and fourth brachials (syzygial pair) 
about half again as broad as long, rather longer on the inner than 
the outer side; following brachials to the eleventh wedge-shaped, 
much broader than long, with the anterior and posterior ends strongly 
concave; following brachials becoming more obliquely wedge-shaped, 
after the sixteenth or seventeenth triangular, as long as, or rather 
longer than, wide, after the proximal third of the arm becoming 
wedge-shaped again and more elongate, somewhat “ dice-box shaped,” 
and distally still more elongate, less and less obliquely quadrate, 
and more and more “ dice-box shaped.” Syzygia occur between 
the third and fourth, ninth and tenth, and fourteenth and _ fif- 
teenth brachials, and distally at intervals of two (more rarely 
three) bifascial articulations. The lower brachials have the distal 
edges strongly and prominently everted and spinous, standing out 
vertically from the axis of the arm, giving it a characteristic scal- 
loped dorsal outline; this condition, however, dies away after about 
the sixteenth brachial, the distal edges of the joints becoming almost 
smooth, although they may be seen, under a strong glass, to bear a 
fringe of short, fine spines. . 
First pinnule 6 mm. long with 20 to 25 joints, very slender, the first 
3 or 4 joints about as long as broad, the remainder becoming pro- 
gressively elongated and exceedingly long and slender distally; after 
the fourth or fifth joint the distal ends become greatly expanded and 
widely flaring, overlapping the bases of the succeeding joints; this 
flaring of the distal ends is confined to the distal ends of the Joints, 
arising rather suddenly; the distal end of a joint is usually about 
twice the diameter of the remainder; the pinnule of the first syzygial 
pair (first inner pinnule) may be similar or it may be twice as long 
as the first pinnule; the second pinnule is 4 mm. long, considerably 
stouter than the first, tapering evenly from the base to the tip, with 
10 joints, the first 3 squarish, the remainder becoming progressively 
elongated; the distal ends of the joints are not especially prominent ; 
third pinnule about the same length, but rather stouter (especially — 
