262 THE VOYAGE OF H.M.S. CHALLENGER. 
‘2. Rhizocrinus rawsont, Pourtalés, 1874 (Pl. IX. figs. 3-5; Pl. X. figs. 3-20; 
Pl. LIIL. figs. 7, 8; woodcut, fig. 19). 
1872. Rhizocrinus lofotensis, Wyv. Thoms. (pars), Proc. Roy. Soc. Edin., vol. vii. p. 770; The Depths of 
the Sea, 1873, p. 450. 
1874. Rhizocrinus Rawsonii, Pourtalés, Ill. Cat. Mus. Comp. Zodl., vol. iv., No. 8, p. 27. 
1882. Rhizocrinus rawsoni, P. H. Carpenter, Bull. Mus. Comp. Zodl., vol. x., No. 4, p. 173. 
1883. Democrinus Parfaiti, Perrier, Comptes rendus, t. xcvi., No. 7, p. 450. 
1883. Rhizocrinus rawsoni, P. H. Carpenter, Ann. and Mag. Nat. Hist., ser. 5, vol. xi. p. 335. 
1884. Rhizocrinus rawsoni, P. H. Carpenter, Proc. Roy. Soc. Edin., vol. xi. p. 357. 
Dimensions.* 
Greatest length of entire specimen (Captain Cole), . - ; - 190°0 mm. 
Greatest length of stem, sixty-eight joints (“ Blake” specimen), : TSO op 
Greatest length of calyx (“Blake”), . ; - : 3 : OHO" 55 
Greatest diameter of same calyx, 5 ; - : . : TED ee 
Greatest length of arm, sixty double joints (Captain Cole), . ‘ a OP 
Stem robust, bearing few radicular cirri on its lower part, but ending below in a long 
spreading root which attaches itself at intervals. The joints are from once and a half 
to twice (rare) as long as broad, and tolerably cylindrical or barrel-shaped in outline. 
The planes of the articular ridges at their ends cross one another, but the ends are not 
much expanded, so that the dice-box shape is but little marked. The calyx is very 
variable in form, sometimes long and slender, sometimes short and broad. The expansion 
from below upwards is rarely quite uniform, and there is often a more or less defined 
constriction about the level of the basiradial suture. The basals are separated by 
distinct sutures, and are generally four or more times the height of the radials, which are 
five in number, and more or less distinctly pentagonal. 
The arms may have one hundred and twenty joints united in pairs by syzygy. The 
first brachials are flattened, quite free laterally, and wider than long. The second are 
more nearly square, and the next four shorter but of about the same width, the last one 
(or the epizygal of the third syzygial pair) often bearing the first pimnule. The following 
hypozygal joints are obliquely oblong; while the epizygals are more irregular in shape, 
and sometimes almost triangular, so as to look like axillaries. The first pinnule is 
generally on the sixth or eighth brachial, but sometimes not till the fourteenth. The 
two lowest joimts of the basal pinnules are broader than their successors, which are 
elongated and of gradually diminishing width. 
The peristome is about at the level of the sixth brachial, and is protected by small 
oral plates. 
Colour, in spirit, brownish-white or greyish-white. 
Localities.—H.M.S. “ Porcupine,” 1869. Station 42. Off Cape Clear, lat. 49° 12’ N., 
? Some other measurements of particular details will be found on p. 265, where also reference is made to the 
unusually elongated calyx of the individuals dredged by the “ Trayailleur.” 
