A MONOGRAPH OF THE EXISTING CRINOIDS 267 



are convex except for flat strips along the lateral edges. The lateral edges are straight 

 and the sides are flattened. There are four IIBr series, one on each of four rays; three 

 of these are 4(3+4) and one is 2. 



There were originally 14 arms. Only 5 arms, aU 3 of one ray and two, which have 

 been regenerated, of another remain nearly complete. It is impossible to say how long 

 the arms were in life. An incomplete arm of 36 brachials measures 40 mm. The first 

 two brachials of an arm arising directly from a IBr axillary are shaped like the IIBr] 

 and IIBr 2 described above. Those of an arm arising from a IIBr axillary are roughly 

 rectangular except that the distal interior corner of each is produced. They are nearly 

 or quite three times as broad as long. The first syzygial pair (composed of brachials 

 3+4) is rectangular and may be twice as broad as long. The brachials immediately 

 following are slightly wedge-shaped, more than half again as broad as long; those farther 

 out are nearly triangular and as long as broad. The brachials are smooth. There are 

 detached pieces of the outer arm which show that the outer brachials are of the shape of 

 those just described, with their distal edges slightly produced. 



In the one remaining arm of those springing directly from a IBr axillary syzygies 

 occur between brachials 3+4, 7+8, and 15+16, and thereafter at intervals of 4 or 5 

 muscular articulations (as far as the thirty-second brachial, at which the arm is broken 

 off). In an arm springing from a IIBr axillary, complete to the thirty-eight brachial, 

 the syzygies occur between brachials 3 + 4, 11 + 12, 19+20, 30 + 31, and 37+38. In 

 fragments of the more distal parts of the arm syzygies occur at intervals of from 4 to 8 

 muscular articulations. 



No P D remains complete. The least damaged is of 24 segments and is 8 mm. long. 

 The first segment is large, more than twice as broad as long, and flattened exteriorly. 

 On the following ten segments there is a gradual decrease in width; the eleventh is 

 nearly as long as broad. The more distal segments are small and even, nearly as long 

 as broad. All the segments, but particularly the larger proximal segments, are carinate 

 dorsally; the carination of each is produced a little toward the next. P t is 14 mm. long, 

 and is composed of 34 segments of which the first six or seven are heavy, nearly twice 

 as broad as long, but gradually decreasing in size. The other segments are small, very 

 gradually decreasing in size, all slightly broader than long. All the segments are faintly 

 carinate. There is not such a contrast between heavy basal and lighter distal segments 

 as there is in P D . P 2 is about 9 mm. long, of 17 segments. The first eight segments 

 are large, wider than long, and faintly carinate dorsally. The remainder are smaller, 

 rounded, longer than broad, and gradually increasing hi length. The genital pinnules 

 are about 8 mm. long with 13-15 segments. The first two segments are short, and 

 the third and fourth are larger, the largest in the pinnule, considerably broader than 

 long. The distal dorsal end of each, but particularly of the fourth, is raised and pro- 

 duced a little. The fifth segment is narrower, roughly as long as broad. There is an 

 abrupt transition between the first five and the following segments; the sixth and 

 following are regular, laterally compressed, narrow, longer than broad, and slowly 

 increase in length so that the distal segments are nearly twice as long as broad. The 

 more distal pinnules are about 10 mm. long with 15-17 segments of which all but the 

 first two are similar, rectangular, slightly longer than broad, and slowly decreasing 

 in size. 



