12 BtTLLETIN 82, UNITED STATES NATIONAL MUSEUM VOLUME 1 



in length to the seventh which is half as long as wide. The tenth is as long as broad; 

 the eleventh to the fourteenth slightlj^ longer than broad. The remaining coluninals 

 gradually decrease in length. Only faint traces of the encircling girdles of the columnals 

 remain. The articulating surfaces of the two ends of the columnals, or at least the 

 longer ones, are broadly oval with the longer axis of one end at right angles to that of 

 the other; this is only just perceptible. 



The sides of the basiradial cup are nearly straight; its height is about half its 

 distal diameter. The basals are considerably longer than the radials. The radials, 

 except for the posterior pair, are in broad contact with one another; beyond the parts 

 of the lateral edges which are in contact they narrow a little. The middle of the wide 

 distal edge is indented for the articulation of the costal; it occupies about a half the 

 distal edge of the radial. The lateral edges of the posterior radials meet proxiinally, 

 but are cut away beyond to allow room for the radianal plate; it follows that both the 

 radials are asj'mmetrical, and they are equally so. 



The radianal plate is diamond-shaped and longer than broad. Its proximal half 

 is in contact with the radials and costals; the distal half lies on the anal tube, which 

 is much wider than it and has gently converging lateral edges and a straight distal 

 margin. It is very near the edge of the disk; the level of the radianal plate is only a 

 little below that of the radials. 



The narrow end of the posterior oral may be seen beyond the anal tube, far below 

 its level, curving over the disk. The other oral plates bend sharply in over the disk 

 and rapidly narrow in their distal halves; they are separated from the radials by a 

 narrow naked strip of perisome. The surface of the ^\ader proximal part of each oral 

 is pitted and some of the pits carry glandular sacs. 



The arms are of 15 or 16 brachials with large side- and covering-plates and irreg- 

 ularly arranged sacculi. On the distal portions of some arms there is one sacculus to 

 each segment. The rudiments of pinnules arise from the eleventh and succeeding 

 brachials. 



The largest specimen has the crown 9 mm. long and the column 13 mm. There 

 are 38 columnals and a large lobed terminal plate. The first columnal has a single 

 radial whorl of cirri of unequal lengths. The anterior and left anterior are of about 

 22 segments and reach to the first brachial, the right anterior is somewhat shorter, 

 the left posterior is broken; tlic right posterior is a rudunent a thu-d as long as the 

 basal plate. The cirri arise from sockets which incise the columnal for its entu-e 

 length. The second columnal is as wide as, and longer than, the first. There are 

 indentations in both its proximal and distal margins opposite the larger cirri of the 

 first columnal. The remainder of the column resembles that of slightly younger 

 specimens. The columnals of the middle part of the stem are each encu-cled by a 

 narrow median girdle. 



The radials are in complete lateral contact. The radianal plate is far out of 

 contact with the posterior radials, being separated from them by the naked perisome; 

 its proximal edge is opposite the distal end of the costals. It is an oval plate resting 

 on the anal tube, which extends some way beyond it— to opposite the end of the first 

 brachial. The posterior oral plate is clearly visible behind the anal tube. The proxi- 

 mal borders of the orals of other interradii are opposite a point halfway along the axil- 

 lanes, so that they are widely separated from the radials by an area of perisome; a 

 numljcr of plates are present in it. The oral plates are of coarse texture, with their 



