A MONOGRAPH OF THE EXISTING CRINOIDS 47 



it arises from nearly or quite the entire dorsal surface of the segment, and its apex is 

 subterminal or median. The terminal claw is about as long as the penultimate seg- 

 ment, and is rather stout basally but is abruptly decurved and becomes compara- 

 tively slender in its distal half. 



The radials are four or five times as broad as long, and their anterolateral angles 

 are sUghtly separated. The IBr, are oblong, twice as broad as long. The IBrj (axil- 

 laries) are pentagonal, nearly or quite as long as broad, with a slight transverse median 

 constriction. The IIBr series are 2, and resemble the IBr series. The elements of the 

 division series and the first brachials bear comparatively short, though thick, ventro- 

 lateral processes. The division series are well separated. 



There are 17 arms 90 mm. long. The arms are comparatively slender and delicate, 

 increasing slightly in width to the twelfth or fourteenth brachials, thence gradually 

 tapering distally. The first two brachials are subequal, wedge-shaped, about twice 

 as broad as the exterior length. The first brachials are interiorly united for about the 

 proximal two-thirds. The first syzygial pair (composed of brachials 3 + 4) varies from 

 slightly longer than broad to slightly broader than long. The following three to five 

 or six brachials are oblong, about twice as broad as long, those succeeding becoming 

 very obUquely wedge-shaped, almost triangular, half again as broad as long, and in 

 the distal part of the arm nearly or quite as long as broad. There is a slight develop- 

 ment of small spines along the distal edges of the brachials. 



Syzygies occur between brachials 3 + 4, again from between brachials 21+22 to 

 between 30 + 31, and distally at intervals of from 9 to 25 (usually about 14) muscular 

 articulations. 



P, is small, slender, and weak, 5 or 6 mm. long, composed of 18-20 segments of 

 which the second, third, and fourth bear broad carinate processes. The first four 

 segments are broader than long, the fifth is about as long as broad, and those following 

 are slightly longer than broad, becoming about half again as long as broad distally. 



Pa is stout and stiff, 9 mm. long, with 15-18 segments, and is much the largest 

 pinnule on the arm, though it is not nearly so stout as m most of the alUed species. 

 The first two or three segments are broader than long and those following are about 

 as long as broad, distally becoming shghtly longer than broad. The distal ends of the 

 segments are slightly produced and finely spmous, especially in the outer part of the 



pinnule. 



The pinnules succeeding are small and weak, 4 mm. long with 11 segments of which 

 the first two are broader than long, the third is about as long as broad, and those 

 following slowly increase in length, becoming half again as long as broad distally. 



The distal pinnules are very slender, 9 mm. long with 20 segments which distally 

 become twice as long as broad or somewhat longer. 



The color in alcohol is purple \vith the cu-ri and Pj yellow and the other pinnules 



white. 



Notes.— The preceding description was drawn up from the specunen from 

 Mauritius in the Berlin Museum collected by Professor Mobius. 



The four specimens from Mauritius in the British Museum upon which Professor 

 BeU's original description was based have 21, 19, 14, and 12 arms. Pj is comparatively 

 slender. The proximal segments of the lower pinnules are strongly carinate. 



One of the four specimens from the Seychelles in the British Museum has 22 arms 



