A MONOGRAPH OF THE EXISTING CRINOIDS 15 



time taking on a rounded character dorsally. The opposing spine is terminally 

 situated, erect or directed slightly forward, arising from the whole surface of the 

 penultimate segment, and in height equal to about half the width of that segment. 

 The terminal claw is considerably longer than the penultimate segment and is stout 

 and slightly curved. 



The radials are much produced anteriorly in the interradial angles of the calyx, 

 entirely separating the bases of the IBri. The division series are deep, strongly and 

 smoothly rounded dorsally, and very widely separated. The first segments following 

 the earlier axillaries are ulteriorly united for about the proximal half, the distal halves 

 of their inner borders diverging widely. After the succeeding axillaries progressively 

 more and more of the inner edge of the ossicles is involved, until in the free undivided 

 arms we usually find the first brachials entirely united interiorly. The division series 

 and arms are rather strongly compressed laterally. 



The 72 arms are 135 mm. long. The first brachials are broader than long, the 

 second are about as long as broad, and the first syzygial pair (composed of brachials 

 3+4) is oblong and longer than broad. The brachials following are oblong and nearly 

 twice as broad as long for the first seven or eight, then triangular and over twice as 

 broad as long, after the proximal third of the arm becoming wedge-shaped and very 

 short. 



P! is 22 mm. long, not particularly stout, though much the stoutest pinnule on 

 the arm, evenly tapering and composed of 33 segments of which the first is short, the 

 third is about as long as broad, and those following are about hah again, later nearly 

 twice, as long as broad. P 2 is 3.5 mm. long, delicate and weak, evenly tapering, and 

 is composed of about 8 segments. The next four pinnules are similar and those 

 succeeding gradually increase in length, the distal reaching 12 mm. The distal 

 pinnules have 25 or 26 segments of which the first two are short and rather broad and 

 the remainder are about half again as long as broad, becoming twice as long as broad 

 in the terminal portion. On the outermost arm of each IIIBr series P t is much larger 

 than the corresponding pinnule on the inner arms, or than P a on the same arms. 



The disk is very deeply incised, with a very long and slender anal tube. 



The color in alcohol is deep violet, the division series with perceptibly darker 

 lateral lines. The alcohol itself is stained light red. 



Another specimen from Singapore has 70 arms about 120 mm. long and the 

 cirri 60-70 mm. long. 



Of the three other specimens from Singapore one has 60 arms 105 mm. long. 

 The outermost branches from the IIBr series have, as usual in this species, one more 

 axillary than the inner. The cirri are XXIII, 45-60, from 50 to 60 mm. long. The 

 anal tube is 15 mm. high. The color is nearly white with the perisome light brownish 

 gray; the division series show traces of slightly darker lateral lines. Another has 65 

 arms 130 mm. long. The cirri are XL, about 70, from 60 to 70 mm. long. P, is from 

 20 to 22 mm. long and is composed of 30 segments. P 2 is 4 mm. long with 8 or 9 

 segments. The anal tube reaches a height of 15 mm. above the disk. The color is 

 deep violet. The third specimen consists of the calyx, centrodorsal, and arm bases 

 of a medium-sized example. The disk has been lost and is just beginning to regenerate, 

 having reached approximately the stage figured by Bell in the type specimen of 

 Zygometra microdiscus . 



