22 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 40. 



median dorsal line ; dist ally this carination gradually narrows antero- 

 posteriorly so that on the last four or five segments preceding the 

 penultimate there is only a blunt median spine ; opposing spine usually 

 rather longer and sharper than the spines on the preceding segments, 

 terminal or subterminal, directed obliquely forward, half as long as 

 the lateral diameter of the penultimate segment ; terminal claw some- 

 what longer than the penultimate segment, stout and strongly curved 

 basally but becoming straighter and more slender in the distal two- 

 thirds. 



Radials almost entirely concealed in the median line, but visible as 

 a very low broad triangle in the angles of the calyx; IBr t very short, 

 bandlike, five or six times as broad as long, in close apposition later- 

 ally; IBr 2 very broadly pentagonal, twice as broad as long; IIBr 4 

 (3 + 4), well rounded dorsally; ossicles of the IBr and IIBr series as 

 far as P D in lateral apposition, though not especially flattened; syn- 

 arthrial tubercles obsolete. 



Fourteen arms (in the type) about 160 mm. long; first brachial 

 very short, slightly wedge shaped, almost entirely united interiorly; 

 second brachial larger, more obliquely wedge shaped ; third and fourth 

 (syzygial pair) oblong, two and one-half to three times as broad as 

 long; following five or six brachials oblong, three to four times as 

 broad as long, then becoming wedge shaped, moderately oblique, 

 about three times as broad as long, soon gradually becoming less and 

 less oblique, in the outer part of the arm being very short, three or 

 three and a half times as broad as long, only slightly wedge shaped. 



P D 11 mm. long with thirty-three segments, moderately stout 

 proximally but rapidly tapering and becoming very slender and 

 flagellate in the distal half; segments at first nearly three times as 

 broad as long, but gradually increasing in length and becoming 

 nearly or quite as long as broad in the distal third; P x 13 mm. long 

 with twenty-six segments, considerably stouter than P D and tapering 

 much less rapidly; the second-eighth segments are strongly carinate; 

 P 2 22 mm. long with thirty segments, similar in general to P x though 

 much larger and stouter and tapering less rapidly ; proximal segments 

 broad, becoming about as long as broad on the tenth or twelfth and 

 remaining so until near the tip ; the second-fifth segments are strongly 

 carinate; P 3 13 mm. long, much smaller and more slender than P 2 ; 

 P 4 somewhat smaller than P 3 ; P 5 9 mm. long, somewhat smaller than 

 P 4 ; the proximal carination occurs on the second-sixth segments; the 

 following pinnules very slowly become more slender, at the same 

 time gradually increasing in length; the distal pinnules are 10 mm. 

 long; the distal carination of the proximal segments, which is very 

 marked on the earlier pinnules, gradually becomes less and less 

 marked, involving fewer and fewer segments; it is but slightly evident 

 beyond P 20 . 



The color is a uniform purplish or violet black. 



