A MONOGRAPH OF THE EXISTING CRINOIDS 283 



Description. — The usual form of this species as it occurs off northern Cuba may 

 be described as follows: The centrodorsal is broad and discoidal with the broad dorsal 

 pole more or less stellate and studded with small tubercles; the sides show five more or 

 less pronounced interradial ridges. The cirrus sockets are arranged in 10-15 more or 

 less irregular columns, usually 2 or 3 to a column. 



The cirri are XX-XXX, 15-19, about 30 mm. long. The first segment is short, 

 the second is about twice as broad as long, the third is about as long as broad, and the 

 fourth and fifth are about half again as long as broad; the following segments gradually 

 decrease in length, becoming distally about as long as broad. The third and one or 

 two of the following segments have a more or less prominent constriction in their 

 distal half, causing them to appear somewhat "dice-box shaped." The remaining 

 segments have a slight prominence of the distal ends and a strong dorsal overlap. 

 The dorsal profile of the distal half of the cirri is strongly serrate, although dorsal 

 spines are not developed. The distal dorsal edge of the segments is sometimes fur- 

 nished with a low ridge or a pair of low tubercles, one on each side. The opposing 

 spine is well developed. The terminal claw is about as long as the penultimate segment, 

 stout, and moderately curved. 



The ends of the basal rays are visible as very irregular tubercles in the angles of 

 the calyx. 



The radials and most, or even all, of the IBri are concealed. The IBr! when visible 

 are very short and bandlike. The IBr 2 (axillaries) are low-triangular, two and one-half 

 to three times as broad as long. Both ossicles are thickly covered with a mass of very 

 irregular more or less confluent tubercles and blunt spines which often renders the 

 delimitation of the ossicles a matter of some difficulty. In the median line there is a 

 very irregular keel or a line of somewhat larger tubercles. The IIBr series are either 

 2 or 4(3 + 4), or both in varying proportions in the same individual. They have the 

 same ornamentation as the IBr series. IIIBr 2 series are usually present resembling 

 the IIBr series and developed internally in 1,2,2,1 order. The division series and first 

 three brachials are in close apposition and sharply flattened laterally. 



The 15-30 (usually 21-30) arms are 120-160 mm. long. The first brachial has a 

 large median tubercle and a more or less tubercular dorsal surface. The second brachial 

 is somewhat less rough. The third brachial is smooth except for the median tubercle, 

 with the distal edge prominently everted and coarsely tubercular. The following 

 brachials as far as the tenth are similar but with the median tubercle less marked and 

 the coarsely tubercular character of the distal edge more accentuated. The first 10 

 brachials are oblong, about twice as broad as long, those following becoming wedge- 

 shaped, longer than broad, with the distal edges strongly overlapping and bluntly 

 serrate. After the proximal third of the arms the brachials become triangular, and 

 distally wedge-shaped again and somewhat elongate. The basal third of the arm is 

 somewhat compressed laterally. 



Syzygies occur between brachials 3+4 (or 1+2, rarely 2+3, after a 4[3 + 4] series), 

 again in the vicinity of brachials 25+26, and distally at intervals of 6-14 (usually 

 about 8) muscular articulations. 



P D (when present) is 12 mm. long with about 30 short compressed segments of 

 which the first six are about twice as broad as long and strongly flattened exteriorly 



