Bd. VI: 8) 
THE CRINOIDEA. 
19 
Station 20 (54 12' S. 36° 50' W. South Georgia. 250 m.) . . . . 1 small specimen. 
22 (54 17' » 36° 28' » » » 75 »).... 2 specimens. 
» 34 (54 ii' » 36° 18' » » » 252 — 310 m.) • • i specimen. 
All the specimens are in poor condition. Some of them are banded, white and 
dark brown, on arms and cirri, and spotted with the same color on the disk. One 
of the smaller specimens from Station 5 has only 18 arms, another only 19, while a 
larger specimen from the same locality has 23 arms. 
The arrangement of the ambulacral furrows on the disk is very variable, hardly 
two specimens being alike. The normal condition, evidently, is that each primary 
ambulacral furrow divides so as to provide four arms; but often one or two of them 
(mostly the left posterior and the right anterior) divide so as to proceed to 6 arms, 
while others go only to two arms. The point of bifurcation may be at any distance 
from the mouth, from close to the edge of the disk to very near the mouth, or the 
furrow to some of the interpolated armpairs may proceed directly from the circum- 
oral furrow, so that there is apparently six or more primary ambulacral furrows. - — 
It would be of considerable interest to study the mode of formation of the ambulacra 
of the interpolated arms: unfortunately the material in hand does not afford the oppor- 
tunity for that, even the youngest specimen (only 5 mm. diameter of disk) having 
already the 20 arms fully formed. 
A. H. CLARK regards Pr. Vanhoffenianus Minckert and Pr. Joubini Vaney 
as synonyms only of Pr. kerguelensis. The present material does not warrant 
forming a definite opinion about the correctness of that view. I cannot, however, 
omit pointing out that in all the specimens in hand the cover plates of the pinnule- 
ambulacra are entirely absent. This fact is certainly not in favour of the identity of 
Pr. Vanhoffenianus with Pr. kerguelensis. A. H. CLARK (Op. cit. p. 132) maintains 
that the presence of the cover plates is a sign of immaturity; I am not very con- 
vinced that it is a universal rule that these plates are more developed in the younger 
than in the grown specimens of Comatulids. In any case it should be emphasized 
that also in the smallest specimen in hand the cover plates are absent. 
One of the specimens is infested with Myzostoma cysticolum V. Graff, a very 
large cyst being found at the base of the third right posterior arm, close to the edge 
of the disk. 
After the full account of this remarkable Myzostoma given by R. v. STUMMER- 
TRAUNFELS 1 and Ch. L. BOULENGER 2 there is no reason to enter in a more detailed 
1 R. v. Stummer-Traunfels. Myzostomidæ. National Antarctic Expedition. IV. Zoology. 1908. 
2 Ch. L. Boulenger. Myzostomidæ. British Antarctic (»Terra Nova«) Expedition. Zoology. II. 
No. 6. 1916. 
