220 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



ventrally. The last 6-8 segments before the penultimate have a slight terminal 

 dorsal tubercle which on the antepenultimate becomes a minute conical terminal 

 dorsal spine. The opposing spine is minute, conical, centrally situated, erect, more 

 slender and sharper than the spine on the preceding segment. The terminal claw 

 is almost or quite half again as long as the very small penultimate segment, slender, 

 and more strongly curved proximally than distally. 



The ends of the basal rays are visible in the interradial angles as very small 

 tubercles separating the exceedingly narrow subradial clefts. 



The radials are only visible as very narrow triangles, with the inner apices more 

 or less near the mid-radial line. The bases of adjacent triangles that is, that 

 portion of the lateral edges of the radials that projects beyond the centrodorsal- are 

 separated by a V-shaped gap in which is a conspicuous pore separating the proximal 

 angles of the IBr^ The IBr! are regularly oblong, about four times as broad as 

 long. The IBr 2 (axillaries) are triangular, with the lateral angles truncated and 

 forming short sides which make an obtuse angle with those of the IBr^ the 2 

 distal sides, which make with each other approximately a right angle, are slightly 

 concave. The IIBr series are 4 (3 + 4); in the type the 2 on the left anterior ray 

 are 2 and the other 8 are 4 (3 + 4). They are narrow and widely separated; the 

 IIB^ are interiorly in close contact in the proximal half, the distal halves of their 

 inner sides diverging at usually approximately a right angle. The IIIBr series are 



3 (2 + 3); in the type there is 1 IIIBr series composed of a single axillary ossicle and 



4 which are 3 (2 + 3). 



The 25 arms of the type are 95 mm. long. The first brachial is about twice as 

 long exteriorly as interiorly, with the inner edge straight and wholly free. The 

 first syzygial pair (composed of brachials 2 + 3) is approximately oblong, from half 

 again to nearly twice as broad as long. The next 4 brachials are oblong, about 

 three times as broad as long, and those following are triangular, with the distal apex 

 rather abruptly produced, half again as broad as the maximum length. After about 

 the proximal fourth of the arm the brachials gradually become short wedge-shaped, 

 about twice as broad as the maximum length, and the terminal brachials are wedge- 

 shaped and about as long as broad. 



Syzygies occur between brachials 2 + 3, from between brachials 12 + 13 to 

 between brachials 14 + 15 (usually between brachials 13 + 14), and distally at intervals 

 of usually 4 muscular articulations. On one arm following the IIIBr 1 series the 

 first 2 brachials form a syzygial pair. On the 2 adjacent inner arms arising from 

 the IIBr 2 series syzygies occur between brachials 2 + 3 and 4 + 5, but on the outer 

 arms the first syzygy is between brachials 2 + 3, as usual. On an arm arising from 

 a IIIBr 3 (2 + 3) series syzygies occur between brachials 2 + 3, 4 + 5, 6 + 7, and again 

 between brachials 13 + 14. 



The lower pinnules are unusually slender. P D is about 22 mm. long, abruptly 

 stouter basally than P! and considerably longer; the second segment has a slight 

 carinate ridge. The first 2 segments of PI have a conspicuous carinate process 

 which in both is extended distally beyond the end of the segment. P 2 and P 3 are 

 smaller and more slender than P! ; their first 2 segments are somewhat enlarged and 

 bear high and conspicuous carinate crests, which on the first extend distally and on 



