384 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



fewer segments, XIII-XVI, 8-10, and short, 7 or 8 mm. in length; the arms are much 

 elongated and slender, with proportionately longer brachials, and without the broad- 

 ening of the proximal portion, reaching 150 mm. in length; the intersyzygial interval 

 is from 3 to 6 (usually 3 or 4) muscular articulations; and the segments of the oral and 

 genital pinnules are rather strongly carinate. Although this carination is not so 

 excessive as it is in the preceding form, it is very noticeable. It is most marked on 

 the second segment, becomes gradually less and less marked distally, and disappears 

 at about the middle of the pinnule. The carinate processes are surmounted by a 

 tuft of fine spines. 



The color in alcohol is flesh color; or yellow with, in the proximal fourth of the 

 arm, a broad lateral line, in the distal three-fourths a zigzag mediodorsal line, of 

 purplish gray; or yellow; or brownish. 



This form bears a strong superficial similarity to the species of the genus Antedon, 

 especially to A. petasus. 



Specimens of this type were examined from Albatross stations 2167 (3), 2330 

 (13), 2333 (8), from Grampus station 5104 (1), and from Bibb station 143P. 



Description of the meridionalis form. The centrodorsal is discoidal, moderate in 

 size, thin to moderately thick, with the flat polar area about 3 mm. in diameter and 

 usually slightly pitted. The cirri are arranged in from 1 to 2 closely crowded irregu- 

 lar marginal rows. 



The cirri are XX-XXVII, 11-12 (usually 12), from 7 mm. to 9 mm. long. The 

 first 2 segments are about twice as broad as long, the third and fourth are from one- 

 third again as long as broad to somewhat over half again as long as broad, usually 

 nearer the latter, and the succeeding segments decrease very gradually in length, 

 those after the sixth being approximately equal, usually about one-third again as 

 long as broad, though sometimes but little longer than broad. The antepenultimate 

 segment is somewhat longer than that preceding, and is oblong in lateral view. The 

 penultimate segment is shorter than that preceding the antepenultimate, slightly 

 broader than long or about as long as broad. There are no dorsal spines or other 

 processes. The opposing spine is very small and delicate, median and erect. The 

 terminal claw is about as long as the antepenultimate segment, and is moderately 

 stout and rather strongly curved. The segments after the second are slightly or 

 moderately constricted centrally so that the articulations are more or less prominent, 

 this feature becoming gradually less marked distally. 



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

 of the calyx. 



The radials are concealed by the centrodorsal, or are just visible over the ends of 

 the basal rays. The IBr! are very short, and are usually more or less concealed by 

 the centrodorsal; they are united laterally for nearly their whole length. The IBr 2 

 (axillaries) are triangular, usually about twice as broad as long or slightly broader, 

 free and rounded laterally. 



The 10 arms, which are stout basally and taper rapidly, are 65 mm. in length. 

 The first brachials are very short, very slightly longer exteriorly than interiorly, 

 almost oblong, interiorly united for about two-thirds of their length, the distal thirds 

 diverging at rather more than a right angle. The second brachials are slightly larger 



