A MONOGRAPH OF THE EXISTING CRINOIDS 255 



quite so broad basally as the sockets, distally narrowing and ending in a point at about 

 the level of the third or fourth cirrus socket. The columns of each radial area are 

 closely crowded against, and tend to alternate with, the columns of the adjacent areas. 



The cirri are XL, 25-26, about 40 mm. long. The first segment is very short, 

 the second and third are equal in size, about twice as broad as long, the fourth is slightly 

 longer, the fifth is as long as broad, and the sixth, seventh, and eighth are the longest, 

 from slightly longer than broad to about one-third again as long as broad ; those follow- 

 ing very gradually decrease in length so that those in the distal half are about as long 

 as broad, or in some cases slightly broader than long. The third segment from the 

 distal end of the cirri is slightly longer than broad; the antepenultimate segment is 

 about one-third again as long as broad; the penultimate segment, which is somewhat 

 less in diameter than the segment preceding, is half again as long as broad. The 

 distal dorsal edges of the outer segments show an inclination to develop low blunt 

 tubercles. The opposing spine is represented by a small blunt tubercle, terminally 

 situated. The terminal claw is long, about as long as the penultimate segment, and is 

 moderately curved. The cirri are rounded in cross section proximally and moderately 

 compressed in the distal two-thirds. There is no trace of dorsal carination. 



The ends of the basal rays are visible as large rhombic tubercles in the angles of the 

 calyx. 



The radials are concealed. The IBri are short, four or five times as broad as 

 long, chevron-shaped, in close lateral apposition, and have more or less wavy proximal 

 and distal borders ; the apposed edges are somewhat thickened and produced, and there are 

 a few low and broad tubercles on the distal border. The IBr 2 (axillaries) are rhombic, 

 twice as broad as long, rising to a rather sharp dorsoventrally elongated tubercle with 

 the IBri. The IIBr series are 4(3+4); on three of the IIBr series the syzygy between 

 the two outer elements is replaced by a synarthry. The IIIBr series are 2(1+2), 

 developed interiorly. The division series are strongly rounded dorsally and have a 

 slightly indicated median carination; they are in very close lateral apposition and 

 their lateral edges are slightly produced and everted. 



The 32 arms are 150 mm. long. The first two to four brachials are oblong, short, 

 united in syzygial pairs which are not quite so long as broad. The two or three follow- 

 ing brachials are oblong, somewhat over twice as broad as long, those succeeding 

 becoming wedge-shaped, twice as broad as long, and slightly longer and more oblique 

 after the proximal third of the arm, when the brachials develop slightly prominent 

 distal ends. 



P D is from 17 to 20 mm. long, very slender and flagellate distally, composed of 

 50-53 segments, of which the two first are disproportionately large, twice as broad as 

 long, and are strongly flattened exteriorly, the third is about half as broad as the first 

 and half as long as the second, twice as broad as long, and those following to the fif- 

 teenth decrease in diameter and increase in length, being at first twice as broad as long 

 but becoming after the fifteenth uniformly small and about as long as broad. PI is of 

 about the same length with 45 segments, similar but much less stout basally and not 

 tapering so rapidly. P 2 is 13 mm. long with about 30 segments, about as stout basally 

 as the preceding pinnule but tapering much more gradually; the first eight segments 

 are about three times as broad as long, those following gradually becoming longer and 

 about as long as broad on about the eighteenth, and terminally longer than broad. 



