A MONOGRAPH OF THE EXISTING CRINOIDS 9 



The radials are narrowly bandlikc, interradially somewhat bent outward by the 

 interradial stripes on the centrodorsal. The IBri are four times as broad as long, with 

 a median carination and provided both proximally and distally with a vertical 4-5- 

 lobed calcareous plate composed of the produced and everted ends of the ossicle. The 

 IBr 2 (axillaries) are twice as broad as long, rhomboidal, in the proximal portion with a 

 well-defined strong median tooth appearing in lateral view as a high bidentatc crest 

 which, together with the disto-median tubercle of the IBri, forms a strong synarthrial 

 tubercle. The distal edge of the IBr 2 is obtusely angled with 6 or 7 pointed prominences. 

 The IIBr series are 2, similar to the IBr series but with smaller and weaker synarthrial 

 tubercles. 



The probably 20 arms arc 65 mm. long, indistinctly flattened laterally. The first 

 six brachials are smooth, but bear both proximally and distally prominent lamelli- 

 shaped lobate prominences similar to those on the ossicles of the division series. In 

 addition, the most proximal brachials are partly with a median dorsal prominence which 

 more distally develops into a dorsal spine, and partly with a pair of similar mediolateral 

 prominences alternately most developed on the left and on the right sides. These 

 lateral tubercles, situated on both sides of the median dorsal spine, disappear at the 

 fifteenth to twentieth brachials, and from this point onward only the median dorsal 

 spine remains. The distal brachials are rather strongly compressed laterally. About 

 five of the terminal brachials have rudimentary pinnules. 



Syzygies occur between brachials 3+4, and 22 + 23; or between brachials 3+4, 

 35+36, etc., with a distal intersyzygial interval of 6-11 muscular articulations. 



PI is 8 mm. long with 12 or 13 segments of which the first 5-7 are concave on the out- 

 side, the concavity bordered by a more or less lobate winglike prominence, and the 

 sixth and following are a little longer than broad, smoother, with a smaller wing and 

 somewhat spiny distal collars. P 2 is 5.5 mm. long with 11 segments. P 3 is 4.5 mm. 

 long with 6 segments. P 4 is a little longer than P 3 with 7 segments. The distal pinnules 

 are 5 mm. long with 12 segments of which the first and second are short and those fol- 

 lowing from half again to twice as long as broad, the two terminal short again. The 

 pinnule segments are smooth, in the proximal portion triangular in section, in the distal 

 rounded. 



The disk is encrusted with coarse granules. 



The soft parts are dark brown, the skeleton lighter brown. 



Notes. The preceding description, adapted from Gisl6n, is based upon a specimen 

 from Bock's station 56 with probably 20 arms, but with two of the branches from a 

 IBr axillary broken. 



A specimen from Bock's station 56 has the cirri XX, 57-61, 20-25 mm. long; 

 dorsal spines are developed from the twelfth segment onward. The arms are about 

 20 in number, 65 mm. long. The JBr axillary is rhomboidal. After about the tenth 

 brachial the dorsal spine is the only remaining prominence. 



Syzygies occur between brachials 3+4 and" 31 + 32; or between brachials 3+4, 

 6 + 7, 32 + 33, etc. The distal intersyzygial interval is 8-11 muscular articulations. 



P! is 7.5 mm. long with 13 segments. P 2 is 5 mm. long with 10 segments. P 3 is 

 4 mm. long with 8 segments. P 4 is 3 mm. long with 7 segments. P 5 is 3.5 mm. long 

 with 8 segments. The distal pinnules are 6 mm. long with 11 segments. 



