A MONOGRAPH OF THE EXISTING CRINOIDS 231 



The cirri are XX, 17-20, from 20 to 25 mm. long, and stout. The first segment 

 is very short, the following gradually increasing in length to about the seventh which, 

 with the following, is about twice as broad as the median length, or in the longest 

 cirri half again as broad as the median length. The dorsal profile of the segments 

 beyond the seventh or eighth is convex, becoming gradually more strongly so toward 

 the end of the cirri where the segments are very bluntly carinate. 



The ends of the basal rays are visible as flat triangular or irregular areas in the 

 angles of the calyx. 



The radials are entirely concealed, or slightly visible as small irregular tubercles 

 or flat irregular areas in the interradial angles. The IBri are short, broadly chevron- 

 shaped, the proximal and distal borders parallel, about four times as broad as long; 

 the proximal edge is produced into a thin border overlapping and concealing the proxi- 

 mal portion of the centrodorsal, though flush with its general surface; the border of 

 this produced edge is usually irregularly scalloped or bears a few low coarse teeth, 

 though it may be nearly plain; it may be evenly curved, becoming straight just over 

 the ends of the basal rays, or it may be regularly curved in its lateral third but nearly 

 straight in its median third; the middle of the dorsal surface of the IBrj is occupied 

 by a large and prominent oval well rounded tubercle. The IBr 2 (axOlaries) are 

 broadly rhombic with the lateral angles truncated so that the lateral edges are from 

 one-half to two-thirds the length of the sides of the IBr b two and one-half times as 

 broad as long, in the median line nearly twice as long as the IBr^ the center, except at 

 the anterior angle, is occupied by a tubercle which is more elongated dorsoventrally 

 than that on the IBr x and, though as high, is less prominent as it rises much less 

 abruptly. The lateral edges of the elements of the IBr series are turned slightly out- 

 ward. The lateral thirds of the proximal edge of the axillaries and the corresponding 

 portions of the distal edge of the IBri are also turned upward to the same height as the 

 lateral edges; the eversion of the latter is most marked just over the ends of the basal 

 rays and gradually decreases anteriorly to the distal corner of the lateral edge of the 

 axillary, persisting, however, as far as the fifth brachial. The inner lateral edges of 

 the first five brachials are similarly modified. 



The 10 arms are 165 mm. long. The first brachials are wedgeshaped, slightly longer 

 exteriorly than interiorly, twice as broad as the exterior length. The proximal border 

 is narrowly produced. The outer border is produced like the lateral borders of the IBr 2 . 

 The inner border is similarly produced, especially at the distal angle, which is more 

 or less rounded off and overlaps the pro.vmal inner angles of the second brachials. The 

 second brachials are of about the size and shape of the first, with the outer edge similarly 

 produced; the production of the inner edge is like that of the outer, but it is not so 

 marked. The first syzygial pair (composed of brachials 3+4) is oblong, about twice as 

 broad as long, with the lateral edges turned outward as in the brachials preceding. 

 The following brachials are slightly wedge-shaped, about twice as broad as long. 

 One brachial between the ninth and thirteenth (usually the eleventh) is oblong, and 

 those following quickly become triangular, about as long as broad. The first four 

 brachials have a low and very broadly rounded median carina! ion, which is very 

 obscure; those following have an equally obscure slight and very broad convexity in the 

 middle of the dorsal surface which, after the eighth or ninth, becomes smaller in area 

 and resolves itself into a low rounded tubercle which gradually disappears after the 



