26 Clark — Seventeen New East Indian Crinoids. 



distal edge is prominently everted, especially in the central third where 

 the eversion is thickened and distally concave, standing up vertically 

 from the dorsal surface of the segment; the third and fourth brachials 

 form a syzygial pair winch is slightly longer on one side than on the 

 other, and is about twice as broad as the lesser length ; this syzygial pair 

 resembles the primibrachial pseudosyzygial pair, but the tubercle just 

 within the proximal border is only barely indicated ; the following three 

 brachials arc slightly wedge-shaped, about twice as broad as the median 

 length, with their distal borders everted as described for the second 

 brachial, but progressively less and less so; the following brachials are 

 triangular, about as long as broad, with slightly produced and overlap- 

 ping distal edges. From the fourth to the ninth brachials there is a low 

 median carination which after the ninth becomes the low rounded zigzag 

 keel characteristic of the arms of all the species of this genus, which is 

 traceable throughout the entire length of the arms. 



Pc is 6.5 mm. long with fifteen segments, rather stout nasally, but 

 tapering rapidly to a very delicate tip, strongly prismatic; the first seg- 

 ment is much broader than long, the following gradually increase in 

 length becoming about as long as broad on the fourth or fifth and termi- 

 nally twice as long as broad ; the second to the sixth segments have a 

 narrow sharp carination, the crest of which is straight and parallel to the 

 longitudinal axis of the pinnule ; the outer edge of the prism formed by 

 the pinnule is sharp; the outer surface of the pinimlars between the 

 prismatic angles is flat or very slightly concave; Pi is similar, 6.5 mm. 

 long with thirteen or fourteen segments; P a is 11 mm. lung with fifteen 

 segments, much larger and stouter than the preceding, tapering evenly 

 from the base and becoming very delicate distally ; the first segment is 

 much broader than long, the following gradually increasing in length and 

 becoming about as long as broad on the fourth, and three times as long 

 as broad terminally; the second, third and fourth have a low even cari- 

 nation ; the second and following have their distal edges all around pro- 

 duced and finely spinous ; P2 is 11 mm. long with fifteen segments, 

 exactly resembling P a ; P& is from 8 mm. to 10 mm. long with nineteen 

 segments, of which the basal are as small as the basal segments of P 2 ; 

 the first segment is short, more or less crescentic, the second is about 

 twice as broad as the median length, the third is not quite so long as the 

 distal breadth, the fourth is from one-third to one-half again as long as 

 broad, and the following gradually increase in length, after the eighth 

 being three or four times as long as broad; the fifth and following have 

 slightly produced and spinous distal edges ; P3 is 10 mm. or 11 mm. long, 

 similar to P/> ; Pc is 8 mm. long with seventeen segments, very slender 

 (more slender than P&) with more elongated segments than P& ; P4 is 

 similar to P c ; Pd is 7 mm. long with eighteen segments, resembling P c , 

 but even more delicate, with longer segments; P5 is similar to P<j ; P e is 

 6.5 mm. long, with sixteen segments, and resembles Pd ; Pc is similar to 

 P e ; the distal pinnules are 8.5 mm. long, with twenty segments, and are 

 excessively slender. 



Type locality. — "Siboga" Station No. 1(>7. 



