8 
VICTORIA MEMORIAL MUSEUM. BULLETIN NO. I 
sionally to swell up slightly, so as to fit into a corresponding de- 
pression on the upper face of the pentamere below. 
The Root is said by Billings to have “identically the appear- 
ance of the radix figured as that of Rhodocrinus asperatus” 
(Canad. Org. Rem., Decade IV, pi. i, f. 4 c-d; 1859). The 
following differences from that figure, however, are to be noted. 
The lumen is not nearly so wide. The root-branches do not 
appear so suddenly or decidedly. The vertical series of penta- 
meres are not observed to split so that half of one joins with half 
of another to form a rootlet. On the contrary only two divisions 
of the root can be seen, after prolonged preparation, and each of 
these is composed of two whole vertical series of pentameres. 
What happens to the fifth series is uncertain. The appearance 
is as though the distal end of the stem had been pressed so as to 
split it apart along two or three of the vertical sutures. The 
two root-branches cannot be traced to their ends, and their 
structure cannot be ascertained; but a broken section across one 
seems to show that it was tripartite, and that the lumen was 
relatively much smaller than that of the stem. 
GENERAL CONCLUSIONS. 
The chief alteration of view to which this renewed study has 
led me relates to the Radials. 
Mr. Billings (1887) regarded all the radials as simple, except 
the right posterior, which he described as compound. 
In “British Fossil Crinoids, II” (April, 1890, Ann. Mag . Nat. 
Hist,, p. 334 and pi. xiv) I suggested a “far simpler and equally 
probable” interpretation of the second plate in the r. post, ray, 
as homologous with the four other plates on a level with it and 
generally resembling it in form. That is to say, accepting the 
ideas of Mr. Billings as to the radials and brachials of all the other 
rays, I regarded the first or lowest plate of the r. post, ray as 
homologous with the radials, and the second plate as homolo- 
gous with the proximal brachials. In 1900 (“Treatise on Zoo- 
logy,” III, Echinoderma, p. 178) I repeated the analysis origin- 
ally based on that of Mr. Billings, as well as the above suggestion; 
but, having by then had the privilege of seeing the hoiotype, I 
was a little more cautious. 
Now, as in 1890, I consider that the first and second plates of 
the r. post, ray are homologous with the plates corresponding 
