A MONOGRAPH OF THE EXISTING CRINOIDS 



575 



broader than long, the second is also from about as long as broad to slightly broader 

 than long, and the third is about as long as broad; the fourth segment tapers distally 

 and is longer than the width of the proximal end. The fifth and following segments 

 are twice as long as broad, becoming three or four times as long as broad distally. 

 The second-fourth segments have a narrow knifelike keel that disappears at the distal 

 end of the latter. 



P 2 is 6-7 mm. long, with 16-20 segments. It is slender, but stouter and stiff er than 

 PI, tapers more gradually, and is composed of proportionately longer segments, which 

 at first are about as long as broad but become three or four times as long as broad 

 distally. The second-fourth segments are narrowly but conspicuously carinate. 



P 3 varies from about the same size as P 2 and similar to it in specimens not fully 

 developed to markedly longer and stouter than P 2 . In the specimen from the Danish 

 Expedition to the Kei Islands station 54, P 3 is 10 mm. long, with 18 segments, and is 

 stouter than P 2 . The first segment is about as long as broad, the second is slightly 

 broader than long, the third is about one-third again as long as broad, and the fifth 

 and following are four or five times as long as broad. The second and third segments, 

 and the basal portion of the fourth, are carinate. 



P 4 is 3-7.5 (usually 3-4) mm. long, small, weak, and flexible, more slender than P 3 

 and tapering more rapidly, with 13-15 segments, of which the first two are slightly 

 broader than long, the third is one-third again as long as broad, the fifth is twice as 

 long as broad, and those following are three times as long as broad, becoming longer 

 distally. The second and third segments are carinate. 



The pinnules immediately following are small, weak, and flexible, 3-4 mm. long, 

 with about 13 segments, of which the first-third are more or less evidently carinate. 

 P 4 may resemble these pinnules or be intermediate between them and P 3 . 



The distal pinnules are delicate and are about 5 mm. long. 



Notes. Professor Bell thus described Antedon vicaria: 



Bidistichate, with wall-sided radials, strong pinnules, and about 30 cirrus-joints, of which the 

 more distal are spiny. With so much resemblance to A. [ = Ptilometra] macronema, it has shorter 

 cirri (20 mm.) and has [ = less] numerous (30) [cirrus-] joints. Arms probably about 25 in number. 

 Neither radial nor distichal palmars [^axillaries] syzygial. Cirri white, arms white with middle 

 dorsal line of purple, pinnules purplish. 



Spread 100 mm. [that is, the arms 50 mm. long]; diameter of deeply incised disc 4 mm. 



I examined Bell's type specimen at the British Museum in 1910. The cirri are 

 XXIII, 29-31 (usually 29), slender, 20 mm. long. Long, sharp dorsal spines are 

 developed from the ninth or tenth segment onward. The longest cirrus segments, 

 just before the development of the dorsal spines, are about twice as long as broad. 

 The 24 arms are 60 mm. long. The dorsolateral ornamentation of the division series 

 and arm bases occupies exactly the same areas as in M. subcarinata, but it is much 

 more prominent and more irregular. Instead of having a finely and evenly tubercu- 

 lated surface the sides of the postradial series are converted into a spongy looking 

 mass, which causes the edges of the rays to appear denticulate. The median keel on 

 the division series and brachials is much higher than it is in M. subcarinata. The 

 arms and division series have a narrow dark-purple median line. When developed 

 the IIIBr series are always external. The disk is covered with small plates. 



