PART 5 A MONOGRAPH OF THE EXISTING CRINOIDS 535 



than broad. The longer earlier segments have slightly flaring ends which overlap 

 the bases of those succeeding. The distal segments increase slightly in width from the 

 pro.ximal to the distal end, tiie dorsal profile being almost straight and continuous 

 with the profiles of the preceding and succeeding segments, the ventral profile forming 

 an angle at the distal end, where it extends below the base of the following segment. 

 The short distal segments are rather sharply carinate dorsally. The penultimate 

 segment is slightly longer than broad; the opposing spine is represented by a broad 

 blunt tubercle. The terminal claw is about as long as the penultimate segment, 

 rather slender and slightly curved. 



The cirri decrease in length from the peripheral to the apical, the latter (all broken) 

 being apparently scarcely half the length of the former. 



The ends of the basal rays are visible as very small rounded-triangular tubercles 

 in the interradial angles. 



The radials are very short with the distal border rather strongly concave so that 

 the anterolateral angles extend well up into the interradial areas, where they separate 

 entirelj' the bases of the IBr,. The distal half is turned outward, especially in the 

 lateral portions. The IBri are short, about four times as broad as the median length, 

 with the lateral edges slightly convergent and widely separated from those of their 

 neighbors and the distal edge slightly concave, incised by the posterior projection of 

 the axillary, with which it forms an apically well-rounded synarthrial tubercle, the 

 sides of which in profile make an angle of about 120° with each other. The IBr2 (axil- 

 laries) are about as long as broad, with the proximal sides nearly straight and making 

 an angle of about 90° ■with each other, and the distal sides strongly concave so that the 

 distal angle and the lateral angles, which extend well beyond the anterolateral angles 

 of the IBr,, are acute. The edges of the elements of the IBr series are smooth, the two 

 distal edges of the axillaries slightly everted. 



The 10 arms are probably a Httle more than 100 mm. long. The first brachials are 

 short, about three times as long exteriorly as interiorly; the short interior sides of each 

 pair make a straight line with each other. The second brachials are about half again 

 as large as the first, approximately triangular, with the pro.ximal angle incising the 

 first and making with it a synarthrial tubercle which resembles that on the IBr series 

 except that the ape.x is more sharply pointed. The first syzj^gial pair (composed of 

 brachials 34-4) is about half again as broad as long with, like the first and second 

 brachials, slighth^ everted and finely spinous ends. The next four brachials are wedge- 

 shaped, about twice as broad as the median length, with the longer side about twice as 

 long as the shorter. Following the second syzygy the brachials soon become more 

 obhquel.y wedge-shaped, almost triangular, and nearly or quite as long as broad. The 

 distal ends of the brachials arc very finely spinous, but are not everted or produced. 

 Distally the brachials become somewhat less obliquely wedge-shaped and longer. 



Syzj'gies occur between brachials 3-f4, 9-|-10, and 14-f 15, and distally at intervals 

 of usually 3 muscular articulations. 



Pi is about 15 mm. long, slender, tapering rather more rapidh' in the pro.ximal 

 than in the distal half and becoming very flexible in the distal third, with 33 to 34 short 

 segments, of which the first five are broader than long and the remainder are shghtly 

 longer than broad. The first five or sLx have the dorsal side convex and finely spinous, 

 and those following until near the tip are very slightly constricted centrally. P2 is 

 similar to Pi but stouter and sliglitly longer with 24 to 27 segments, which distally are 



