A MONOGRAPH OF THE EXISTING CRINOIDS 149 



following are about one-third again as long as broad. The antepenultimate segment 

 is a little longer than broad. From about the seventh segment onward there is a slight 

 dorsal transverse carination which on the twelfth-fourteenth becomes a little thickened 

 on either side of the median line, appearing as two inconspicuous tubercles visible only 

 by high magnification. From the fifteenth-twentieth segment onward there is a 

 single swelling which disappears on the outermost segments. The penultimate seg- 

 ment is about as long as broad. The height of the opposing spine varies from one- 

 third to one-half the width of the penultimate segment. The terminal claw is half 

 again as long as the penultimate segment, and is curved and pointed. The radials 

 are visible as very narrow bands beyond the rim of the centrodorsal, and are laterally 

 united in the proximal half. The IB^ are from three to four tunes as broad as long, 

 and are laterally free. The IBr 2 (axillaries) are pentagonal, half again as broad as 

 long; with the IBr! they form a small synarthrial prominence with an indistinctly 

 delimited tubercle which is not at all, or only very slightly, prominent in lateral view. 

 The 10 arms are from 40 to 45 mm. long, and smooth. The first brachials are inte- 

 riorly united basally. The first ten brachials are discoidal, not "wall-sided," and 

 those following have oblique ends. On the articulation between the first two brachials 

 there is a prominence similar to that on the IBr series. Syzygies occur between 

 brachials 3+4, 9 + 10, 14 + 15, etc., and distally at intervals of 3 (exceptionally 

 only 2) muscular articulations. PI is from 3 to 5 mm. long with 13-15 segments 

 which are smooth and vary from as long as broad to half again as long as broad. 

 P a is from 5 to 6.5 mm. long with 16 segments, longer and stouter than Pj, the middle 

 segments often with small distal tubercles. P 3 is from 3 to 4 mm. long with 12 seg- 

 ments, and is smooth like the pinnules succeeding. P 4 is of the same length as P 3 

 or shorter, with 13 segments. P 6 and the following pinnules are longer again. P a is 

 absent. P b is 4.5 mm. long with 14 segments. The distal pinnules are 5 mm. long 

 with about 20 segments of which the first two are short, the third is about as long as 

 broad, and those following are long and slender, about twice as long as broad. The 

 disk is 3 mm. in diameter, incised, smooth, and without calcareous granules. The 

 color as preserved is light brown. In another specimen from Bock's station 13 the 

 centrodorsal is knob-shaped, with the bare dorsal pole 1.3 mm. in diameter. The 

 cirri are XXVI, 20-24, from 8 to 10 mm. long. The terminal claw is about as long as 

 the penultimate segment. The IBr 2 (axillaries) are low hexagons, half again as 

 broad as long. The IIBr series are 2. The 12 arms are 40 mm. long. The first 

 8 brachials are discoidal. The intersyzygial interval is 2 or 3 muscular articulations. 

 PI is 3.5 mm. long with 12 segments. P 2 is 5 mm. long with 13 or 14 segments. P b is 

 5 mm. long with 14 segments. P 3 is 3.5 mm. long with 10 segments. P 4 is 3 mm. long 

 with 12 segments. The distal pinnules are 4.5 mm. long with about 15 segments; 

 there is a notch between the second and third segments by which the second seems 

 to form a small prominence. A similar condition, though not so marked, occurs in 

 the specimen preceding. 



In another specimen the cirri are XXVIII, 19-22, about 9 mm. long. The 11 arms 

 are 40 mm. long. P, is 3 mm. long with 11 segments. P 2 is from 3. 5to 4.5 mm. long 

 with 13 segments. P 3 is 2.5 mm. long with 11 segments. P 4 is 2 mm. long with 9 

 segments. The distal pinnules are 5.5 mm. long with 16 segments. 



