A MONOGRAPH OF THE EXISTING CRINOIDS 299 



recognizable through being very much stouter than the slender and delicate grooved 

 pinnules. In contrast to the grooved pinnules, they are capable of being coiled 

 dorsally, and they are commonly found wrapped about the organism to which the 

 animal is clingmg, quite after the manner of cirri. 



In color the 2 specimens first described are yellow. That probably from Perth 

 is light pinkish, becoming rose color on the caly.x and arm bases; the cirri are light 

 pinkish pro.ximally but become rose color beyond the eighth segment. 



Notes. — In the largest specimen from Koombana Bay the centrodorsal is large, 

 thick discoidal, with a broad flat dorsal pole 4.5 mm. in diameter. The cirri are XIV, 

 32-35, 13 mm. long, and are arranged in a single slightly irregular marginal row. 

 They taper gradually to about the eighth segment, being comparatively slender from 

 that point onward. 



The arms are 45 mm. long, very rugged and very stout, increasing gradually in 

 width to about the twelfth brachial, from which point they taper rapidly to the tip. 

 All the arms and almost aU the pinnules possess ambulacral grooves. In this specimen 

 the pinnules resemble the arms in being short. They are stout at the base but taper 

 rapidly in the first 4 segments, being comparatively slender beyond. The distal 

 pinnules are slender but short. 



The two other specunens from Koombana Bay are similar to the one described. 



The specimen probably from Perth is larger than those from Koombana Bay. 

 The centrodorsal is thick discoidal with a large flat polar area 4.5 mm. in diameter. 

 The cirri are XV, 32, 13 mm. long. They taper very noticeably to the eighth segment, 

 but vary slightly or not at all from that point onward. The sixth-ninth segments 

 are the longest, from half again to twice as broad as long. The remaining segments 

 are subequal, all more than twice as broad as long. Up to the eighth the cirrus 

 segments are light in color with a dull unpolished surface, but beyond that point they 

 are deeper in color and possess a distinct polish. There is, however, no definitely 

 marked transition segment. The cirrus segments are perfectly smooth without 

 dorsal spines or other projections, but in lateral view the dorsal profile of the outer 

 segments is seen to be very convex. 



The anterior arms measure 65 mm. in length and the posterior 60 mm. The 

 arms are short, stout, and rugged, tapering rapidly and ending quite abruptly, as is 

 characteristic of the species. 



The mouth is submarginal, just to the right of the base of the right derivative of 

 the anterior ray. 



In the specimen dredged by the Endeavour between Fremantle and Geraldton, 

 which is an unusually fine example, the centrodorsal is thick discoidal with the dorsal 

 pole large, very slightly convex (almost flat), 5 mm. in diameter. 



The cirri are XVIII, 35-37 (usually the latter), from 15 to 18 mm. in length. 

 They are arranged in one (with a partial second) irregular marginal row. All of the 

 component segments are much broader than long. The cirri taper markedly for the 

 first 7 segments. 



The 10 arms are all of equal length and size, 85 mm. long, 2.5 mm. wide at 

 the base, and 4.3 mm. wide at the broadest place, which is between the twelfth and 

 fourteenth brachials. 



