360 . Proceedings of the Boy (d Societij 
so remarkable a character in Rldzocrtnus, are absent.” I find, how- 
ever, that in both species the grouping of the arm-joints is exactly 
the same as was observed in B. carpenteri by Danielssen and Keren, 
if the term “ trifascial articulation ” be substituted for “ syzygy ” in 
their descriptions. In the nine lowest brachials there are alterna- 
tions of a pair of joints united trifascially, and a single joint with 
muscular attachments at each end ; while beyond the ninth brachial 
the two forms of articulation alternate with great regularity. The 
presence of this trifascial articulation, and its peculiar distribution 
may therefore be considered as characteristic of Batliycrinus ; and 
the “alternate syzygies” in the arms, which are supposed to be 
absent in this genus, are really present in a modified form. Keither 
do the arms “resemble in character the pinnules of RMzoerinusf 
or “show no trace of pinnules” in B. gracilis. Tor one or two of 
them have little stumps on their terminal joints, which give them 
the appearance of bifurcation, just as at the growing points of the 
arms of young Comcdnlidae. and Pentacrinidse ; and I see no reason 
to doubt that these stumps are the commencing pinnules. 
: Family Comatulid^e. 
Genus Antedon.^ Frem. 
5. Antedon rosacea, Linck. sp. 
“ Frequent in water of moderate depth,” * One individual 
which seems to belong to this species, though certainly representing 
a rather strongly marked variety, was obtained somewhere in, the 
Korth Atlantic, but the exact record of its locality has unfortu- 
nately been lost. 
Among the numbers of Ant. phalanglum of various ages which 
were dredged in 1870, at 30 to 120 fathoms, on the Skerki Bank, 
and at 50 to 120 fathoms, in the Bay of Benzert, on the Tunis 
coast, were five young specimens certainly not belonging to this 
type, and probably, therefore, to be referred to the Mediterranean 
variety of Ant. rosacea. It is impossible to state now the exact 
depth from which they were collected, but it was probably not 
below 50 fathoms, as Ant. rosacea has not yet been found in the 
* Proc. Ptoj. Soc. Eclin., vol. vii. p. 765. 
