238 



of ti are bordered with exceedinglj fine spines. The synarthrial tubercles, though broadly 



nded, are rather prominent. 



1'hc first brachial is short, three times as long exteriorly as interiorly, slightly longer in 

 the median line than interiorly; the interior edges are in apposition; the exterior edges are 

 slightly concave: the distal inner corners bear a rudimentary tubercle similar to that on the 

 outer part of the lateral borders of the IBr v These tubercles on the H'>r,. with the adjacent 

 tubercles under the lateral angles of the axillaries, almost completely close what otherwise 

 would be a large rhombic water pore. 



Tlv nd brachial is much larger than the first, in direct dorsal view almost an 



equilateral triangle; the outer border is slightly concave; the distal edge is very finely spinous. 



Tlv ti: i.il ]>air (composed of the third and fourth brachials) is slightly longer 



interiorly than exteriorly, about twice as broad as long in the median line, the sides slightly 



ive, the distal edge very finely spinous. The following brachials rapidly become obliquely 



wed| 1. after the second syzygy triangular and as long as broad with very finely spinous 



tnd later obliquely wedge-shaped again. 



ir between the third and fourth, ninth and tenth and fourteenth and fifteenth 

 hials, and distally at intervals of four (more rarely three) oblique musctilar articulations. 



The brachials have projecting and overlapping finely spinous distal edges, and the dorsal 

 e is marked with fine parallel longitudinal ridges. The arms are 120 mm. long. 



1' is from 12 mm. to 13 mm. long, composed of 20 segments of which the first is 

 slightly longer than broad, the second is about half again as long as broad, the third is about 

 as long as the proximal length, and the fourth and following are about two and one 

 halt" times as long as broad; P, is the longest pinnule on the arm, though only slightly longer 

 than the distal pinnules; it is smooth with long segments, rather stiff and moderately stout, 

 tapering moderately in the proximal third, more gradually from that point onward; in its general 

 appearance, especially in the very close union of its segments which have perfectly straight 

 ends, it recalls 1' in the larger species of Psathyr ometra. 



1' is from 10. o mm. to 10.5 mm. long with 17 segments, similar to \\ but tapering 

 rather more evenly. 



1' is S mm. long with 13 or 14 segments, similar to 1', and 1\. bul with the segments 

 more enlarged distally and proportionately smaller. 



1', is 5.5 mm with 12 or 13 segments, similar to P g , but with the distal segments 



slightly more 1 



I' is 5.5 mm. long. ibling the preceding pinnule but more slender, with 12 or 1; 



segments >•( which the distal are more elonsrated. 



1' is - mm. long with 1 n nts, longer, less slender and less stiff than those preceding, 



tal egments with very slightly spinou edges. The following pinnules are similar to I' 



Tlv distal pinnules are lingly slender, 11 mm. long with 23 segments of which 



first two are unusually enlarged and the following are moderately elongate with swoHen 

 .01 1 hm |y spino is ends. 



The specimen described is that from Stat. 253. 



