A MONOGRAPH OF THE EXISTING CRINOIDS 511 



laterally, so that m a lateral view the cirrus appears to thicken from this point onward. 

 The transition and following segments have the distal dorsal edge produced, this 

 production rapidly becoming more sharply rounded and soon angled, the segments 

 at the same time becoming distally more carinate dorsally, so that the later segments 

 are provided with a small but sharp subterminal tubercle. In addition the segments 

 from the eleventh or twelfth onward have, just before their middle, a second, more 

 rounded, median dorsal tubercle which is not quite so high as that in the distal 

 portion. The cirri of this species present, therefore, much the same appearance as 

 those of Oligometrides adeonae. The opposing spine is represented by a small median 

 tubercle arising from the entire dorsal surface of the penultimate segment; in lateral 

 view the apex usually forms slightly more than a right angle, though occasionally it 

 is sharper. The terminal claw is somewhat longer than the penultimate segment, 

 stout basally but becoming more slender distally, and is moderately curved. 



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

 calyx. 



Of the radials only a small portion is visible in the angles of the calyx over the 

 ends of the basal rays. The IBrj are very short and broad, more or less, indeed 

 sometimes wholly, concealed by the centrodorsal ; their lateral edges are just in 

 contact basally, but diverge distally. The IBr 2 (axillaries) are broadly pentagonal, 

 almost triangular, twice as broad as long, or even somewhat broader. The IIBr 

 series are 4 (3 + 4). The IIIBr series are 2. The IVBr series are 2, but are irregular 

 in their occurrence. The division series are free laterally though not widely separated ; 

 they are rounded dorsally but not especially convex. 



The 36 arms are about 100 mm. long. The first brachials are short, wedge- 

 shaped, almost wholly united interiorly, twice as broad as the interior length or 

 slightly broader. The second brachials are similar, but slightly larger. The first 

 syzygial pair (composed of brachials 3+4) is not quite so long as broad. The next 

 2 brachials are oblong, about twice as broad as long, after which the brachials become 

 triangular, about half again as broad as long, after the end of the proximal third of 

 the arm gradually becoming wedge-shaped, and in the terminal portion wedge-shaped 

 and about as long as broad. The fourth and following brachials have strongly pro- 

 duced and finely spinous distal ends. The arms increase gradually in width up to the 

 tenth brachial, thence tapering very gradually distally. 



Syzygies occur between brachials 3 + 4, again usually between brachials 13 + 14, 

 and distally at intervals of 4, more rarely 5, muscular articulations. 



P! is 10 mm. long, slender, composed of 35 segments, of which the first is short 

 oblong, about two and one-half times as broad as long, and those following are rhombic, 

 at first nearly twice as broad as long but gradually becoming longer and about as long 

 as broad after the sixth. The second and following segments have the corners cut 

 away, this feature gradually decreasing distally and disappearing entirely after about 

 the twelfth segment. From the second to the tenth or eleventh the segments have 

 long single or double spines projecting vertically from the dorsal surface which at 

 first are equal to half the width of the segment in height, but slowly decrease in length 

 distally. The terminal comb is short and very prominent, beginning abruptly, and 

 consisting of 6 or 7 teeth which are subequal, triangular, slightly longer than broad, 

 rather strongly recurved, rather longer than the width of the segments that bear them, 



