362 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



the fourth-sixth are nearly twice as long as broad. The segments following slowly 

 decrease in length, becoming about as long as broad on the tenth or eleventh, then 

 broader than long, and distally half again as broad as long. On the fourth or fifth 

 the median portion of the distal dorsal edge projects slightly; this projection increases 

 in amount and moves proximally as a ridge so that in the outer portion of the cirri 

 high carinate dorsal spines are developed. These spines are short, so that they are 

 widely separated from each other; they have the crest finally straight and parallel to 

 the axis of the segments that bear them. On the last 10 or 11 segments preceding 

 the penultimate they become narrowed into prominent median erect conical tubercles. 



The radials extend well beyond the rim of the centrodorsal in the mid-radial line, 

 and are produced interradially, the adjacent sides of two adjoining radials widely 

 separating the bases of the IBri. The sides of these interradial processes are slightly 

 convergent, and the width of the distal edge is more than half the length of the sides 

 of the IBri. The IBr] are from two and one-half to three times as broad as long in 

 the median line. The ventrolateral borders are produced, and the sides of these pro- 

 duced portions are straight and coverge slightly distally. The IBr 2 (axillaries) are 

 somewhat longer than broad. The proximal portion of the ventrolateral border is 

 produced, hi continuation of the production on the IBri, and these lateral processes 

 continue the convergence of those on the IBr t so that they disappear beneath the 

 lateral angles about halfway from the proximal border to the apex. The unusually 

 long axillary is slightly constricted centrally. The distal edges are rather strongly 

 concave, the chords of the concavities making slightly more than a right angle with 

 each other. A low narrow rounded median ridge runs from the proximal border of 

 the IBrj to a point beneath the apex of the axillary. The IIBr series are 2, and are 

 much narrower than the IBr series because of the absence of the projection of the 

 ventrolateral borders. The IIBr! are about as long as broad. The IIBr 2 (axillaries) 

 are about as long as the maximum width. The IIBr series have the same low median 

 carinate lies as the IBr series. There are no synarthrial tubercles. 



The 14 arms are 85 mm. long and very slender; all the brachials are longer than 

 broad. The first syzygial parr (composed of brachials 3+4) is nearly twice as long 

 as broad. A very low and narrow sharp median carination, like a fine hair line, runs 

 the whole length of the arms. 



On an arm arising from a IIBr axillary P! is 7 mm. long, flexible and exceedingly 

 delicate and hauiike. It is composed of 26 segments of which the first two are 

 enormously enlarged. The first segment is about three times as broad as long, 

 including the distal carinate process which is either rounded or sharply pointed, and 

 overlaps the base of the third brachial (the hypozygal of the first syzygial pair). 

 The second segment is about half as broad as the first, and is between two and three 

 times as broad as long. The third segment is scarcely more than half as broad as the 

 second, and is about as long as broad, or slightly broader than long. From the third 

 segment onward the pinnule tapers very gradually to the tip. The fourth and fol- 

 lowing segments are all somewhat longer than broad, but none are so much as half 

 again as long as broad. P 2 is 15 mm. long, stiff and spinelike though very slender, 

 and is composed of 19 segments. The first segment is wedge-shaped with the base of 

 the wedge proximal, and is about twice as broad as the median length. The second 

 segment is slightly longer than broad, and trapezoidal, the sides converging distally. 



