A MONOGRAPH OF THE EXISTING CRINOIDS 481 



axillary are little or not at all stouter than those on the inner arms, but are much 

 elongated. Occasionally all the lower pinnules are slender, Lamprometra palmata 

 palmata intergrading imperceptibly into L. p. gyges. P 2 is usually abruptly longer 

 and stouter than the other pinnules, but occasionally P 3 is nearly as long and almost 

 as much enlarged, and sometimes P, may be nearly as long though always more 

 slender. 



Pi varies greatly in size. It may be small or nearly or even quite as long as P 2 . 

 It is usually one-half to two-thirds as long as P 2 , and is not so stout, tapering more 

 rapidly at the base. On the outer arms it varies from 7 to 12 mm. in length, being 

 usually 9 to 12 mm. long, and is composed of 12-35 (usually 20-25) segments. The 

 basal segments are rather broad, but the pinnule tapers rapidly in its proximal portion 

 and is slender in the distal two-thirds. The proximal segments are broader than 

 long, and the distal are usually not greatly longer than broad. The pinnule is more 

 or less cylindrical and is usually somewhat stiffened, but becomes flagellate at the tip. 

 P a may resemble P 1; or it may be much smaller. P 2 is the longest and stoutest pinnule 

 on the arm and is usually much longer and stouter than either Fi or P 3 ; but it may be 

 scarcely longer than these pinnules and scarcely stouter than P 3 . Occasionally it is 

 slender. It is more or less strongly stiffened, though tapering to a delicate and 

 flagellate tip. It is usually more or less, and often strongly, recurved toward the arm 

 tip, but it may be straight and almost spinelike. It varies from 9 to 18 mm. in length 

 on the outermost arms of the postradial series, being usually between 10 and 15 mm. 

 long. It is composed of 16-40 (most commonly 25-30) segments, which are usually 

 mostly about as long as broad. It may be as much as three times as long as the 

 corresponding pinnule on the inner arms, though it is usually about half again as 

 long and may be of practically the same size. The component segments are smooth 

 and cylindrical, the earlier broader than long and the outermost about twice as long 

 as broad. P b is similar to P 2 but is more or less smaller. 



P 3 is sometimes nearly equal to P 2 in length and stoutness, but it is usually con- 

 siderably shorter and less stout. It may be not so much as half as long as P 2 . It 

 varies from 6 to 10 mm. in length and is composed of 8 to 20 segments. 



P 4 may be similar to P 3 and of almost the same length, or it may be a good deal 

 shorter, only one-quarter as long as P 2 , with a smaller number of segments, sometimes 

 as few as 7 or 8. It is occasionally the smallest pinnule on the arm. 



P 6 and P 8 are 3 to 5 mm. long. The pinnules following gradually increase in 

 length, the distal pinnules being 5 to 8 mm. long and consisting of 19 or 20 smooth 

 segments. 



The disk is 10 to 20 mm. in diameter and is naked and more or less deeply, often 

 very deeply, incised. Sacculi are abundant and usually closely set along the sides 

 of the pinnule ambulacra. 



Notes. — The specimen from the Macclesfield Bank was described by Prof. F. 

 Jeffrey Bell as the representative of a new species, which he called Ante-don moorei. 

 He said : 



This species is probably most nearly allied to A. [Parametra] compressa, P. H. C, but it has only 

 faint spinous processes on the cirrus-joints. Cirri 25 to 30, with 25 joints. Centrodorsal bare in the 

 middle. No syzygies on radkls, distichals or palmars. There may he post-palmars. The third 



