64 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



The cirri are XVI, 20, about 10 mm. long. From the third, fourth, or fifth 

 onward the cirrus segments are about as long as broad. On the fourth or fifth and 

 following segments two transverse ridges, a proximal and a distal, are developed which 

 in lateral view appear as two small dorsal spines. 



The elements of the IBr series and the first two brachials are broad, and are in 

 close lateral apposition all along their edges. The IBr series and arm bases of this 

 species are most strikingly similar to those of the species of Tropiometra. 



The 10 arms are about 50 mm. long. The first two brachials are broad and are 

 in close apposition with those on adjacent arms. PI is the longest and stoutest pinnule, 

 8 mm. long with 13 segments of which the first is slightly broader than long, the second 

 is trapezoidal, tapering distally, slightly longer than the proximal (greater) width, 

 the third is about twice as long as the proximal width, the fourth and fifth are about 

 three times as long as broad, and the remainder are from two to two and one-half 

 times as long as broad. The pinnule tapers evenly from the base to the tip, and is 

 distinctly prismatic, with the dorsal ridge rounded, for its entire length. P 2 is 6.5 

 mm. long with 12 segments, similar to PI but proportionately less stout. P 3 is 

 5.5 mm. long with 10 segments, and is similar to P 2 . These three pinnules are con- 

 siderably stiffened. P 4 is 4 mm. long with 12 segments of which the first is over 

 twice as broad as long and those following gradually increase in length, becoming 

 about as long as broad on the fourth and twice as long as broad distally. The pinnule 

 is slightly less stout basally than P 3 and tapers more rapidly. It is weak and not 

 stiffened. The following pinnules have more numerous and shorter segments. P 10 

 is 4.5 mm. long with 17 segments which at first are short, becoming about as long as 

 broad on the ninth or tenth. The distal pinnules are very slender, about 4.5 mm. 

 long with 17 segments. 



The color in alcohol is violet as far as about the sixth brachial, thence yellow 

 with a narrow median line of white; the outer half or two-thirds of the proximal 

 pinnules is yellow. 



The specimen described is the most perfect example from Siboga station 273. 



An individual similar to the preceding, with arms 50 mm. long and cirri 11 mm. 

 long, is olive-brown, gradually becoming yellow-brown after the second syzygy. 

 There is a narrow median line of white on the arm bases as far as the second syzygy. 



Another specimen is entirely deep violet with the ends of the cirri and pinnules 

 yellowish. A fourth example is deep purple with narrow yellow bands on the arms 

 and a more or less obsolete narrow mediodorsal line of yellow on the arm bases. A 

 fifth is purple with large white blotches on the arms and a fine white mediodorsal 

 line. Still another is entirely orange-yellow. The remaining two specimens from 

 Siboga station 273 resemble one or other of those preceding. 



Notes. Professor Bell said that in the specimens from Port Curtis and Port 

 Denison a white line which extends along the middle of the IBr series, the rest of which 

 is of a reddish purple, is continued for a short, though varying distance along each 

 of the arms. 



In the specimen from Alert station 87 the cirri are about XX, 21. The transverse 

 ridge has moved so far back that it is near the proximal end of the cirrus segments, 

 and the distal dorsal border of the segments has become prominent so that the bi- 

 dentate appearance, hi lateral view, is produced. 



