A MONOGRAPH OF THE EXISTING CRINOIDS 13 



twice as broad as long. The sixth-eighth and following segments have the distal 

 dorsal edge everted in the shape of an open V-shaped ridge, which is composed of an 

 apical round tubercle and two lateral more or less elongate tubercles. Distally this 

 ridge gradually becomes less and less V-shaped and is composed of four or five tubercles, 

 the apical tubercle, however, remaining in the same position and therefore occupying a 

 position below the center of the now almost straight tubercular ridge. As the segments 

 decrease in length distally the apical tubercle gradually disappears, and the transverse 

 ridge moves gradually to a median position. On becoming median it at first has usually 

 four tubercles, this number being later reduced to three, while beginning on about 

 the fifteenth from the end there are only two, the last three or four segments before the 

 penultimate bearing only a single median tubercle. The opposing spine is compara- 

 tively large, arising from the entire dorsal surface of the segment, with the apex sub- 

 terminal ; it is equal to about half the width of the penultimate segment in height. The 

 terminal claw is somewhat longer than the penultimate segment and is rather stout 

 and strongly curved. 



The radials are short in the midradial line but extend far up into the angles of 

 the calyx, reaching the disk and separating the bases of the IBr^ The IBr, are slightly 

 trapezoidal, about twice as broad basally as long, and are well rounded dorsally and very 

 widely separated laterally. The IBr 2 (axillaries) are pentagonal, about as long as 

 broad. The IIBr series are 2, only one being present. 



The 11 arms are very widely separated; all are broken off at the syzygy between 

 brachials 3+4. The first brachials are slightly wedge-shaped, half again as broad as 

 long, interiorly united for the proximal half or two-thirds, their inner borders thence 

 diverging distally at approximately a right angle. The second brachials are about 

 as long as broad and approximately rectangular. The third brachials (the hypozy- 

 gals of the first syzygial pair) are oblong and three times as broad as long. 



PI is slender, evenly tapering, 15 mm. long, and composed of 20-25 segments of 

 which the first is twice as broad as long, the second and third about as long as broad, 

 and those following are about twice as long as broad, becoming shorter terminally. 



The color in alcohol is purplish brown. 



The specimen from Albatross station 5146 is a particularly fine example with 

 about 120 arms. 



The specimen from New Caledonia is a beautiful representative of the species 

 with 64 arms. The cirri are XXXII, 59-74 ; the dorsal processes begin on the twenty- 

 fifth segment. P! has 46-56 segments. P 2 and the pinnules following have 8 or 9 

 segments and are very short. 



The specimen from Little Kei Island described by Reichensperger is very large. 

 The centrodorsal is thick with the dorsal pole concave; the cirrus sockets are 

 arranged in three rows. 



The cirri are over LX, 60-70, from 60 to 70 mm. long. In the distal half of the 

 cirri the segments are carinate or feebly spiny. 



The postradial series divide occasionally six times. The IBr axillary is only 

 slightly broader than long, and is somewhat constricted centrally. The division 

 series are 2, the distal rarely 4(3+4). The axillaries are almost always centrally 

 constricted. 



The 104 arms are up to 160 mm. long, and consist of 180-190 brachials beyond 



