EEPORT ON THE CEINOIDEA. 261 



SS. "Blake," 1877-78. No. 29, lat. 24° 36' N., long. 84° 5' W. ; 955 fathoms; bottom temperature, 39^'. 

 No. 35, lat. 23° 5' 46" N., long. 88° 58' W. ; 804 fathoms; bottom temperature, 40r. No. 43, 

 lat. 24° 8' N., long. 82° 51' W. ; 339 fathoms; bottom temperature, 40°. No. 44, lat."25° 33' N., 

 long. 84° 35' "VV. ; 539 fathoms ; bottom temperature, 39^°. No. 5G, off Havana, lat. 22° 9' N., long. 

 82° 21' 30" W. ; 175 fathoms. 



1878-79. No. 238, ofif Grenadines, 127 fathoms; fine coral sand; bottom temperature, 56°. No. 248, off 

 Grenada; 161 fathoms; fine grey ooze; temperature, 53J°. No. 259, off Grenada; 159 fathoms; bottom 

 temperature, 53i°. No. 274, ofi' Barbados ; 209 fathoms ; fine sand and ooze ; bottom temperature, 53|°. 



1880. No. 306, lat. 41° 32' 50" N., long. 65° 55' W. ; 524 fathoms. 



U. S. Pish Commission, 1882. No. 1124, S.S.E. off Nantucket; 640 fathoms. 



Remarks. — An elaborate account of this well-known species lias already been given 

 by Sars, and I have little to say about it except on one or two points, (l) The sub- 

 radial portion of the summit is not formed by the top stem -joint as supposed by him, but 

 it consists of anchylosed basals, as was originally described by Pourtales.^ (2) I have also 

 followed Pourtales in considering the two joints immediately above the radials as the 

 two lowest brachials, and not as the second and third (axillary) radials, as they have been 

 called by Sars, Ludwig, and Wyville Thomson. No matter what the number of arms of 

 a Crinoid, the so-called second and third radials are morphologically brachials, as I 

 have already pointed out [ante, pp. 47, 48) ; and though it is convenient for descriptive 

 purposes to speak of the successive divisions of the rays as radials, distichals, and 

 palmars, I see no advantage whatever in calling the two lowest arm-joints of a five-armed 

 Crinoid the second and axillary radials. That they are homologous with the second and 

 third radials of Comatula and Pentacrinus is undisputed, but these are fundamentally 

 brachials ; and as it is the distinctive character of an axUlary joint that it should bear 

 two arms (or arm-divisions) on its distal face, the use of the term " axillary " in the case 

 of a five-armed Crinoid is misleading and unnecessary. 



There is another point in Sars's description that I would just notice. On p. 23 he 

 says distinctly that the covering plates of the ambulacra occur " sur le disque, aussi bien 

 que dans toute la longueur des bras et des pinnules." But there is no sign of them in 

 either of his figures of the disk (Tab. iv. figs. 85, 86, 89). In fact, in fig. 85 no covering 

 plates are represented at all, though the food-groove is showTi as far as the distal part of 

 the second brachial ; while in the other two figures the first covering plate is shown 

 resting on the distal part of the second, or the lower part of the third brachial. 



The form of the calyx in this species varies very considerably ; for it is nearly 

 hemispherical in some specimens and much elongated in others. These last have the 

 best developed arms; and to some extent, therefore, the forms wath a low and wide cup 

 must be regarded as premature. But differences of development will not entii'ely account 

 for the variation, as the calyx of a young specimen found by Sars^ is distinctly higher 

 (longer) than broad. 



' Crinoides vivants. Tab. iv. fig. 95. 



