316 THE VOYAGE OF H.M.S. CHALLENGER. 
ce 
the same character “as occurring in some specimens of Pentacrinus miilleri,” 2.e., the 
type now known as Pentacrinus decorus. 
Filhol continues, however, ‘‘nous avons constaté, apres avoir remonté des débris de 
roches, que ces animaux vivaient, contrairement 4 ce que l’on avait cru pouvoir supposer, 
complétement fixés par des cirres recourbés se détachant de larticulation terminale de la 
tige. Ces sortes de crochets se soudent en quelque sorte avec le fond sur lequel ils 
reposent et il faut les briser pour les détacher, Par conséquent les Pentacrinus Wyville- 
Thompsons (sic), que lon a recontrés libres, avaient di étre arrachés & la suite de quelque 
accident du fond sur lequel ils vivaient, car il parait bien difficile d’admettre que les 
mémes animaux en des points divers de l’océan aient des modes d’existence differents.” 
The observations here recorded are undoubtedly of great value ; but the conclusions 
drawn from them by Filhol appear to me to be somewhat rash. The “Talisman” speci- 
mens of Pentacrinus wyville-thomsoni seem to have been living on a stony or rocky 
bottom ; and in fact Prof. Perrier’ records that “plusieurs ont été ramenées avec les 
cailloux sur lesquels ils sont fixés.” There can be no question therefore that Pentacrinus 
wyville-thomsont lives in a permanently fixed condition on a hard bottom. But the 
“accident” which is supposed by Filhol to have liberated some fifteen fixed individuals 
must have been of a rather extensive character ; and it must further have taken place at 
a sufficiently long time before they were dredged by the ‘“‘ Porcupine” for the lowest nodal 
joint of one of them to have lost its natural appearance (Pl. XXIL. fig. 20) and have 
become enlarged and rounded as shown on Pl. XXII. fig. 27. But in other specimens the 
lowest nodal joint is far less modified, It retains its pentagonal shape and the thickened 
rim of the syzygial face, in the centre of which there is a small rounded tubercle covering 
the opening of the central canal. If all these specimens had been detached by one 
general “accident” anterior to the arrival of the “ Poreupine’s” dredge and tangles 
among them, their lowest nodal joints should haye been in the same condition and not 
in different stages of modification. The same “accident” must have happened to the 
Pentacrinus decorus of the Caribbean Sea and to the Pentacrinus maclearanus of the 
Challenger dredgings, both of which were described by Sir Wyville as having the stems 
closed up at a modified nodal joint ; but Filhol makes no reference whatever to these two 
types. He does not appear to dispute the fact that the “Porcupine” individuals of 
Pentacrinus wyville-thomsoni were free when captured; but he regards the observations 
of the “Talisman” as proving that this condition was not a natural one. Sir Wyville? 
believed that although the Pentacrinus, like the young Comatula, “ was doubtless attached 
in its early days, it appears to have finally parted from its attachment, and to have led a 
free life;” and he pointed out that the syzygial union of the stem-joints at the nodes 
facilitated the rupture of the stem, just as is the case with the syzygies in the arms. His 
} LExpédition du Talisman, Revue Scientifique, No. 24, December 15, 1883, p. 741. 
* Sea Lilies, The Intellectual Observer, August 1864, pave 
