252 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



ginal row. These are deep, and as a rule the lateral borders are more or less straight 

 and may be slightly elevated as a low narrow ridge. 



The cirri are XIII, 17, 9 mm. long. The first segment is three times as broad 

 as long, or even shorter; the second is from half again to twice as broad as long; 

 the fourth is twice as long as the median width and is a transition segment. The 

 fifth is about half again as long as the median width, and the seventh and following 

 are about as long as the basal width. The transition segment is slightly constricted 

 centrally, and the distal end is enlarged. On the dorsal side the distal edge is slightly 

 everted and is armed with exceedingly fine spinules. On the segment succeeding, 

 the distal edge dorsally is much more strongly produced, so that the distal end of the 

 segment is about one-third again as long as the proximal end of the next following, 

 the difference representing the height of the elevation. On the next segment the 

 everted distal end becomes gabled in the middle. On the succeeding segments the 

 distal end of this gable moves proximally, so that the outer segments when viewed 

 laterally show a high curved and very spiny crest running from near the proximal 

 to the distal end. In dorsal view this crest is seen to be one of the sides of a deep 

 V, which extends from the distal end of the segments to more or less near the proximal 

 end. The opposing spine in lateral view is triangular, erect, arising from the entire 

 surface of the penultimate segment, and equal to nearly half the width of the seg- 

 ment in height. Its apex is transversely elongated. The terminal claw is scarcely 

 longer than the penultimate segment and is stout and strongly curved. 



The ends of the basal rays are visible as small interradial tubercles. The radials 

 are concealed in the median line, but a small portion of their anterolaterai angles 

 is visible over the ends of the basal rays. The IBr! are very short, from six to eight 

 times as broad as long in the median line; the proximal border is somewhat convex 

 and the distal border is straight. The IBr 2 (axillaries) are triangular, from two and 

 one-half to three times as broad as long. The lateral angles are slightly truncated, 

 and the distal angle is a right angle. The IB^ are laterally united in their proximal 

 half or two-thirds, but the axillaries are widely free laterally. 



The 10 arms are 80 mm. long. The first brachial is short, slightly longer exteri- 

 orly than interiorly, from six to eight times as broad as the median length, with the 

 proximal and distal edges straight and almost parallel ; interiorly the two first brachials 

 of each arm pair are united in the basal portion, or in the basal half, beyond which 

 their inner sides make usually a right angle with each other. The second brachials 

 are almost triangular, the outer side being twice as long as the outer side of the first 

 and the inner less than half as long as the inner side of the first. Both the first and 

 second brachials have the distal edge slightly everted and armed with very fine 

 spines, and the distal portion of the dorsal surface of the second brachials is marked 

 with numerous very fine more or less parallel longitudinal ridges. The first syzygial 

 pair (composed of brachials 3 + 4) is approximately oblong and is about three times 

 as broad as long. The syzygial line is slightly raised and is finely spinous, and the 

 distal portion of the dorsal surface of the hypozygal is marked with numerous fine 

 ridges. The distal edge of the epizygal is finely spinous. The next 2 brachials are 

 roughly oblong, about four times as broad as long, with finely spinous distal ends, 

 and those following soon become triangular, half again as broad as long, with the 



