538 BULLETIN 82, UNITED STATES NATIONAL MUSEUM VOLUME 1 



Diagnostic features. When the arms are 35-40 mm., the cirri are 34-40, about 

 XLV, up to 12 mm. long and in 15 columns. 



Description. The centrodorsal is a high pointed cone with a sharp and rough 

 dorsal pole; the basal diameter is 2.5 mm. and the vertical height also 2.5 mm.; the 

 proximal border is produced interradially into low angles; it is thickly covered with 

 cirrus sockets, interradially arranged in distinct columns but radially more irregular in 

 position. 



The cirri are XLV, 34-40, the peripheral about 12 mm. long, slightly longer than 

 the apical. The first three segments are about twice as broad as long; the third seg- 

 ment is broader distally than proximally, the greater width being on the dorsal side, 

 and is centrally constricted, more strongly on the dorsal than on the ventral side. 

 The fourth and fifth segments are of similar shape but the fourth is more than half as 

 long as broad and the fifth is nearly as long as broad. The sixth to tenth are slightly 

 longer than broad, broader distally than proximally, but not to the same extent as the 

 third to fifth; they are of a more regular shape, not constricted centrally. The eleventh 

 and twelfth segments are as long as broad. The remaining segments are broader than 

 long. Beyond about the fifteenth segment the dorsal edge becomes curved instead of 

 straight, and on the distal segments it is produced into a strongly rounded dorsal 

 spine. The opposing spine is strong and stands out at right angles. The terminal 

 claw is strong. 



The radials are short and bandlike with concave and everted distal edges. The 

 IBr t are short, about six times as broad as long in the midline, and are in contact 

 laterally; they are deeply incised by the posterior projection of the axillary, with which 

 they rise into a synarthrial tubercle. The IBr 2 (axillaries) are rhombic, a little broader 

 than long; their proximal edges are nearly straight, the distal strongly concave, so that 

 the posterior projection is broadly rounded, the anterior angle sharper. The edges of 

 the elements of the IBr series are everted and finely spinous. 



[NoTE BY A.M.C.: The arms are all broken; their length is estimated at from 35 

 to 40 mm.] 



The first brachial is short, slightly longer externally than internally; the distal 

 edge is slightly incised by a posterior projection from the second brachial, which is 

 approximately an equilateral triangle with the distal edge slightly concave. The 

 inner border of the first syzygial pair (composed of brachials 3+4) is considerably 

 longer than the outer. The fifth to eighth brachials, between the first and second 

 syzygial pairs, are roughly rectangular, somewhat broader than long, alternately 

 longer on one side than on the other. The brachials for some distance beyond the 

 second syzygy are triangular and about as long as broad. Farther out on the arm 

 they are wedge-shaped, slightly longer than broad, with one side, alternating on suc- 

 cessive brachials, considerably longer than the other. The distal edges of the brachials 

 between the first and third or fourth syzygial pairs are produced into single rows of 

 strong toothlike spines; those of the more distal brachials are smooth. 



Syzygies occur between brachials 3+4, 9+10, and 14+15, and distally at inter- 

 vals of 3 or 4, exceptionally 5, muscular articulations. The length from the proximal 

 edge of the IBrt to the second syzygy is 8.0 mm. and the width at the first syzygy is 

 1.4 mm. 



PI is incomplete or hidden. P 2 is slender, with 12 or 13 elongate segments; it is 

 nearly 6 mm. long. P a and P b are each about 5 mm. long. P a is composed of 11 



