A MONOGRAPH OF THE EXISTING CRINOIDS 357 



The cirri are XIX, 39-50, from 35 to 45 (usually about 40) mm. long, large and 

 stout, with a pronounced taper in the distal half. The first 9 or 10 segments are from 

 half again to twice as broad as long, usually nearer the latter, the first being similar to 

 those succeeding. The segments following the ninth or tenth gradually become 

 shorter, but at the tip of the cirri the segments slowly increase in length again. The 

 tenth segment has on the dorsal side just within the distal border an inconspicuous 

 slightly elongated median tubercle which on those succeeding slowly transforms into 

 a narrow and low, though prominent, median carination running the entire length 

 of the segments. On the fifteenth segment two small tubercles appear, one on either 

 side of the median carination just within the distal edge. These increase in size and 

 elongate, after two or three segments becoming prominent low narrow keels which 

 resemble the median keel, though they are slightly less in height and do not extend 

 quite so far toward the proximal border of the segment; they are not quite parallel to 

 the' median keel, but converge slightly toward the proximal end of the segments. 

 Distally all three carinate processes increase in height, especially the median, and a 

 tubercle, which may be more or less elongate, usually appears just outside the distal 

 end of each of the lateral keels. Because of the terminal taper of the cirri the opposing 

 spine and terminal claw are rudimentary. 



The radials are short in the middorsal line but extend upward in the interradial 

 angles in the form of broad processes with parallel or slightly converging sides which 

 entirely and widely separate the bases of the IBr^ these processes are sharply trun- 

 cated distally and are not expanded or spatulate, The IBri are short, oblong, four 

 or five tunes as broad as long. The ventrolateral edge is produced into a thin border 

 which, viewed dorsally, is seen to run from the distal edge of the interradial process of 

 the radials to the distal lateral angles of the IBri where it disappears from dorsal view, 

 being continued along the ventral side of the axillary and of the division series forming 

 a deep trough in which the soft parts lie. The IBr 2 (axillaries) are broadly pentagonal, 

 nearly twice as broad as long. The lateral edges are little, if any, shorter than those 

 of the IBri with which they make a broadly obtuse angle. The IIBr and IIIBr series 

 are 2 ; all the latter are developed. The division series extend outward almost horizon- 

 tally. 



The 40 arms are from 60 to 95 mm. long and resemble those of the other species of 

 the genus. There is little or no overlapping of the distal edges of the brachials. 



PI is 14 mm. long with 28 segments of which the first two are greatly enlarged, 

 over twice the breadth of those succeeding, with the distal edge more or less convex; 

 the third or third and fourth are slightly broader than long; and the remainder are 

 subequal, slightly longer than broad; as a whole the pinnule is proportionately longer 

 and somewhat stouter and stronger than is usual in the genus. P 2 is 18 mm. long with 

 19 segments and resembles P 3 , but is very slightly less stout. P 3 is 19 mm. long, very 

 stiff and spinelike, with 19 segments of which the first two are broader than long, 

 slightly enlarged, with distal carinate processes the edges of which are straight and 

 parallel with the longitudinal axis of the pinnule or nearly so, the third is nearly as 

 long as broad, and those following are elongate with, after the eight, produced distal 

 edges which at the prismatic angles are provided with prominent spines. P< is 14 mm. 

 long with 15 segments and resembles P 3 but is less stout and has the first two segments 

 less enlarged. P B is 10 mm. long with 12 segments and is more slender than P 4 . The 



