PART 5 A MONOGRAPH OF THE EXISTING CRINOIDS 513 



Description of the type material. — The centrodorsal is conical with the tip rounded, 

 longer than broad at tlie base, with the sides divided into .5 radial areas by bare inter- 

 radial lines which basally are almost as broad as the adjacent cirrus sockets, becoming 

 obsolete in the apical half. Each radial area contains four very crowded columns 

 of oval cirrus sockets, 6, 7 or 8 in a coliunn, which are more or less raised above the 

 general surface. 



The cirri are XL-LXX, 30-35, up to 60 mm. long and strongly compressed laterally 

 throughout. The first two segments are about as long as broad, the tliird is twnce 

 as long as broad, the following to the fourteenth are nearlj' four times as long as broad, 

 and the succeeding very gradually decrease in length to the antepenultimate which is 

 about twice as long as broad. The penultimate segment is very small, about as long 

 as broad. The opposing spine is represented by a small conical tubercle, terminally 

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

 very slightly curved. All of the cirrus segments increase slowly in width to the distal 

 end, which is slightly produced. 



The ends of the basal rays are very prominent, continuing anteriorly the bare 

 interradial lines of the centrodorsal in the form of conspicuous bridges between the 

 deep but narrow subradial clefts. 



The radials are short, 5 or 6 times as broad as long in the median line, and their 

 interradial angles are strongly produced anteriorly, entirely separating the bases of 

 the IBri. The tip of the interradial processes of the radials shows a deep U- or V- 

 shaped notch. The proximal borders of the radials are straight and are separated 

 from the centrodorsal by a deep but very narrow cleft. 



The IBri are short, from 3 to 4 times as broad as the median length, with their 

 bases widely separated by the interradial processes of the radials, their lateral edges 

 converging, and the distal border broadly V-shaped. The IBro (a.xillaries) are nearly 

 square, with the anterior sides slightly concave and the cHstal angle truncated; their 

 proximal border is in the form of a right angle incising the anterior border of the IBr,; 

 their lateral angles extend for some distance beyond the anterolateral angles of the 

 IBri. The dorsal surface of the IBr, and IBr2 is very high and strongly arched, and 

 the midline of both rises to the point of union between them, making, in profile, an 

 angle of about 120°. 



The 10 arms are apparently somewhat more than 120 mm. in length. The first 

 brachials are short, with a longer outer than inner edge, deeply concave anteriorly, 

 and with the bases just in contact interiorly. The second brachials are triangular, 

 slighth' longer than broad. The first syzvgial pair (composed of the third and fourth 

 brachials) is nearly as long as broad, very slightly longer inwardly tium outwardly. 

 The next 4 brachials are very slightly wedge-shaped, almost oblong, somewhat more than 

 twice as broad as long, and the following are triangular, about as long as broad, distally 

 becoming wedge-shaped again and finally elongate. 



Syzygies occur between brachials 3+4, 9 + 10, and 14 + 15, and distally at intervals 

 of 3 or 4 muscular articulations. 



Pi is 14 mm. long, slender and evenly tapering, with 20 segments, of which the 

 first is nearly 3 times as long as broad and the remainder are much elongated, the outer 

 with slightly expanded distal ends. P^ is similar, but about 1 mm. shorter. P3 is 

 slightly longer again and somewhat stouter with the first segment about as long as 

 broad, the second nearly or quite twice as long as broad, and the following becoming 



