264 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



broad; the 14-20 arms are 75 mm. long; and the division series and arm bases are 

 smooth. 



Description. The centrodorsal is a truncated hemisphere, marked by indistinct 

 interradial ridges which are produced upward into rather prominent processes between 

 the radials. The cirrus sockets (according to the figure) are arranged hi 10 columns of 

 2 or 3 each, the columns being in close contact interradially but separated by a broad 

 shallow groove in the midradial line. 



The cirri are XX-XXV, 18-23. According to the figure the segments beyond the 

 basal are all longer than broad, most of them about half again as long as broad. There 

 is no opposing spine. 



The radials are concealed. The IBri are quite short, especially in the median line, 

 and are barely in contact above the angles of the centrodorsal. According to the figure 

 they form a deeply U-shaped rather narrow band about the broadly rounded posterior 

 projection of the axillary, which sometimes almost reaches the ceutrodorsal. The 

 IBr 2 (axillaries) are somewhat broader than long, deeply shield-shaped with the distal 

 angle very obtuse, scarcely rising higher than the anterolateral angles, and a long 

 broadly rounded posterior projection. The IIBr series are 4(3+4) and, together with 

 a few of the proximal brachials, are in close lateral apposition and sharply flattened 

 laterally. The first two elements of the IIBr series are somewhat tubercular. 



The 14-20 arms are 75 mm. long and are composed of over 100 brachials of which 

 the lowest are nearly oblong and their successors triangular, broader than long, gradu- 

 ally becoming longer and more wedge-shaped. 



In arms arising from a IBr axillary the first sj^zygy is between brachials 3+4 and 

 the next is from between brachials 12 + 13 to between brachials 16+17. In arms 

 arising from IIBr axillary the first syzygy is usually between brachials 1+2 and the 

 next from between brachials 8+9 to between brachials 26+27, usually about brachials 

 13 + 14 or 15 + 16. The distal intersyzygial interval is from 5 to 13, usually 7 or 8, 

 oblique muscular articulations. 



P D is about 9 mm. long with about 30 short carinate segments the lowest of which, 

 though thick, are not especially broad. The next two or three pinnules are of about 

 the same length with relatively longer distal segments, and the lower ones somewhat 

 flatter. The following pinnules are a little shorter, with the first two segments smaller 

 than in the proximal pinnules; but the third segment and from two to four of its suc- 

 cessors are broad and flattened with the outer edges much produced toward the ventral 

 side. Traces of this expansion may be visible as far as the twenty-fifth brachial, after 

 which the segments become elongated and the pinnules more slender. 



The disk is 7 mm. in diameter, much incised and completely plated, as are also 

 the brachial ambulacra and the mterarticular spaces. The gonads are covered by closely 

 set plates in which sacculi are embedded. These are small and inconspicuous on the 

 pinnule ambulacra, which have well-defined side plates. 



The color in alcohol is light whitish brown. 



Notes. Carpenter's specimens in the British Museum have been examined by 

 Professor Gislen and by myself, but neither of us had anything to add to the original 

 description and figures. 



Locality. Challenger station 214; off the Meangis Islands (lat. 433' N., long. 

 12706' E.); 914 meters; bottom temperature 5.44 C.; blue mud; February 10, 1875 



