A MONOGRAPH OF THE EXISTING CRINOIDS 359 



of the division series have everted borders and the brachials and cirrus segments 

 produced distal ends giving the annual a rough appearance. 



Description. The centrodorsal is thin discoidal with the broad polar area flat 

 and 4 mm. in diameter. The cirrus sockets are arranged in a single fairly regular row. 



The cirri are XV, 31-36, about 25 mm. long, large and stout, their bases crowded 

 against those of their neighbors and their first segments more or less sharply flattened 

 laterally. The first two segments are about twice as broad as long, those following 

 gradually increasing in length and becoming nearly, sometimes quite, as long as 

 broad on the fifth. The next two or three segments are similar, the following very 

 gradually decreasing in length so that those hi the outer fourth of the cirri are about 

 twice as broad as long. In the distal fourth or fifth the cirri taper very gradually so 

 that the tip is comparatively slender. The distal edge of the segments all around is 

 everted and prominently overlapping. From the tenth onward the dorsal surface of 

 the 'segments is sharply carinate. At first this affects only the distal part, but it 

 soon comes to involve the entire dorsal surface of the segments, standing up in the 

 form of a high median keel the crest of which is parallel to the longitudinal axis of the 

 cirrus. On the terminal twelve or thirteen segments the high median carination is 

 accompanied on either side by a usually more or less elongate tubercle which, how- 

 ever, is comparatively small and inconspicuous and much less developed than the 

 corresponding structure in N. gorgonia. 



The radials are even with the run of the centrodorsal hi the midradial line but are 

 strongly produced in the interradial angles where they separate widely the bases of the 

 IBr, ; the distal edge of these anterior processes, which are straight and not spatulate 

 or otherwise modified, is equal in length to the lateral edges of the IBr,. The cirrus 

 sockets encroach more or less upon the radials as do those of Reometra mariae. The 

 division series, which extend out horizontally from the radials, are very narrow and 

 very strongly rounded so that they are very widely separated. The extreme, ventro- 

 lateral border of the ossicles of the division series is produced in the shape of a thin 

 flange with a smooth and sharp outer border which runs from the distal edge of the 

 interradial production of the radials to the second brachial, but the produced borders 

 are dorsally only visible as far as the IBr axillary. From the ends of the interradial 

 processes of the radials these produced borders as viewed ventrally are parallel as far 

 as the IIBr axillary, but as the IIBr series make a very considerable angle with each 

 other they disappear dorsally at the IBr axillary. Extra division series are always 

 external. 



The 30-40 arms are from 70 to 75 mm. long, and resemble those of N. multicolor. 



PI is 10-11 mm. long, slender though not so weak as is usually the case in species 

 of this genus, with 29 segments of which the first two are enormously enlarged, sub- 

 equal, from three to four tunes as broad as long, nearly twice as large as the first two 

 segments of P 2 . The third segment occupies about one-third the distal border of the 

 second and is about as long as broad. The following segments are slightly longer than 

 broad, becoming about as long as broad in the distal half of the pinnule. This pinnule 

 is more or less stiffened. P 2 is 11-12 mm. long, straight and stiff though not par- 

 ticularly enlarged, composed of 18-21 segments of which the fourth and following are 

 about twice as long as broad. The first is about three tunes as broad as long in the 

 median line and about twice as broad basally as the third. The second is about as 



