A MONOGRAPH OF THE EXISTING CRINOIDS 211 



one-third again as broad as long. The segments in the proximal half of the cirri 

 have strongly sinuous distal ends, but the distal ends of those in the distal half are 

 straight, making a considerable angle with the straight proximal ends, so that the 

 distal segments are wedge-shaped in lateral view. The bases of the cirri are much 

 crowded and compressed laterally so that the first segment is very narrow, the second 

 is half again as broad as the first, and the third is slightly broader than the second. 

 From the third segment onward the cirri, as viewed dorsally, taper rather rapidly to 

 the tip. In lateral view the width is uniform throughout. The third-fifth segments 

 bear dorsally a long narrow straight and low transverse ridge just within the distal 

 edge. On the segments immediately following the ends of this ridge curve upward 

 and outward to the distal angles of the segments. These lateral extensions are soon 

 lost, and the ridge gradually again becomes straight and moves to a position near 

 the proximal end of the segments. In lateral view the ridge appears as a small 

 triangular point. The opposing spine is triangular, sharp, and erect, arising from 

 the whole dorsal surface of the penultimate segment; its height is equal to about half 

 the width of that segment. The terminal claw is as long as, or longer than, the 

 penultimate segment, and is rather strongly curved basally, becoming almost straight 

 distally. 



The radials are wholly concealed. The IBr, are very short, between 5 and 6 

 times as broad as long, with straight and parallel proximal and distal borders and 

 slightly diverging lateral edges, which have a slightly produced border. The IBr 2 

 (axillaries) are triangular with the lateral angles truncated. They are very short, 

 about three times as broad as long, with the distal angle obtuse, the distal sides very 

 slightly concave, and the lateral edges, which are slightly shorter than the lateral 

 edges of the IBr,, straight and slightly produced into a narrow thin flange like border. 

 There is a small though well-marked synarthrial tubercle on the articulation between 

 the elements of the IBr series. The IBr series as a whole are short and broad, mod- 

 erately convex dorsally, and in lateral apposition with their neighbors through the 

 slight lateral extension of their margins. 



The 10 arms are 60 mm. long. The first brachials are slightly wedge-shaped, 

 about four times as broad as the median length, with the outer edge from one-third 

 to one-half again as long as the inner. The inner edges are in close contact for their 

 entire length. The second brachials are more pronouncedly wedge-shaped, with the 

 outer edge about as long as that of the first brachials, but the inner edge only about 

 half as long as that of the first brachials. The first syzygial pair (composed of bra- 

 chials 3+4) is about three times as broad as the median length, slightly longer in- 

 teriorly than exteriorly. The next four or five brachials are very short, about five 

 times as broad as the median length, with the proximal and distal sides approximately 

 parallel. The brachials succeeding are sharply triangular, somewhat over twice as 

 broad as the greatest length, in the outer half of the arm becoming very obliquely 

 wedge-shaped with the distal border more or less prominent, later elongating so that 

 the terminal brachials are bluntly wedge-shaped, nearly as long as broad, with very 

 oblique distal ends. The brachials are evenly rounded dorsally, and the first two 

 have slightly produced outer borders by which they are in contact with their neighbors. 



Syzygies occur between brachials 3+4, 9 + 10, and 14 + 15 or 15 + 16, and distally 



