296 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



Description. The centrodorsal is thick discoidal with the bare polar area slightly 

 convex, 4 mm. in diameter. The cirrus sockets are arranged in two closely crowded 

 irregular marginal rows. 



The cirri are XVI, 34-36, from 25 to 30 mm. in length, stout basally, and tapering 

 slightly in the proximal half. The first segment is short, and those following slowly 

 increase in length to the eighth or tenth, which varies from only slightly broader than 

 long to one-third again as broad as long, the distal segments being slightly shorter 

 again. From the eleventh to the fifteenth (usually from about the fourteenth) on- 

 ward small but prominent dorsal spines are developed. The opposing spine is larger 

 than the spine on the preceding segment, triangular in lateral view with the apex 

 sub terminal, arising from the whole dorsal surface of the penultimate segment, and 

 equal in height to about one-half of its width. The terminal claw is somewhat longer 

 than the penultimate segment, moderately slender, especially in the distal two-thirds, 

 and rather strongly curved proximally but becoming straighter distally. 



The radials are concealed by the centrodorsal. The IBr t are very short, band- 

 like, in apposition laterally. The IBr 2 (axillaries) are very broadly pentagonal, 

 twice as broad as long, with the lateral borders only half as long as those of the IBr,. 

 The IIBr series are 4(3 + 4). The division series and the first brachials are in close 

 lateral apposition and laterally flattened, their lateral borders being moderately 

 produced. The synarthrial tubercles are obsolete. 



The 16 arms of the type specimen are 130 mm. long. The first brachials are 

 slightly wedge-shaped, twice as broad as long exteriorly, entirely united interiorly. 

 The second brachials are of about the same size, but are more obliquely wedge-shaped. 

 The first syzygial pair (composed of brachials 3 + 4) is slightly longer interiorly than 

 exteriorly, twice as broad as the exterior length. The next three or four brachials 

 are oblong, three times as broad as long, those following becoming very obliquely 

 wedge-shaped, twice as broad as long, after the proximal fourth of the arm gradually 

 becoming less obliquely wedge-shaped, but never oblong. The eighth and ninth and 

 following brachials have slightly produced distal edges, this feature gradually dying 

 away after the middle of the arm. 



P D is 9.5 mm. long, more slender than P,, tapering more rapidly from the base 

 and therefore more slender in its outer portion, and is composed of 32 segments of 

 which the earlier are short, becoming about as long as broad on the twelfth and 

 following. The second-fourth segments are strongly carinate, and those following 

 are narrowly carinate to about the middle of the pinnule. P, is slender, becoming 

 very delicate in the distal half, 10 mm. long with 26-28 segments of which the first 

 is short and those following gradually increase in length so that the eighth and follow- 

 ing are about as long as broad. The second-fourth segments are rather strongly 

 carinate. P 2 is 12 mm. long, very slightly stouter basally than P, but tapering 

 much more gradually and so appearing considerably stouter, with 27 segments, 

 which become about as long as broad on the sixth and from one-third to one-half 

 again as long as broad distally. P 3 is similar to P 2 but very slightly larger and longer. 

 P 4 is 8 mm. long, resembling P 2 and P 3 but tapering more rapidly and therefore more 

 slender in the distal half. P 6 is 6 mm. long, small and weak, with 16 segments all 

 but the outermost of which are broader than long. The following pinnules are 

 similar, gradually increasing in length and in the length of the component segments. 



