1882. ] CLASSIFICATION OF THE COMATULS. 739 
beyond the palmars. It should read 3 A'/DP(P’) P. There may be 
yet another in Acé. bennetti and the number of arms reach 70 or 80, 
which is only very rarely the case among the Comatule. Prof. 
Bell’s formula (3 A'RDP £)> however, only provides for 40, which is 
a very common condition. The formula should therefore be 
3 A’DPP'(P”) = The same may be said of Act. schlegeli, the only 
known example of which has two axillaries beyond the palmars and 
over 80 arms. Its proper formula would be 3 A’DPP’P” 2 while 
Prof. Bell gives 3 A‘'RDP 2, which provides for less than half 
this number of arms, so that one of the most evident specific char- 
acters is not taken into account at all. 
The ray-divisions of Act. pulchella have been thus described :— 
“10-20 arms, most of the rays usually dividing twice, the first 
division (distichals) consisting of two joints which are not united by 
syzygy. When the arms spring directly from the radial axillary, 
the two lowest brachials are united by ligament, as in most Coma- 
tule, and the third is a syzygial or double joint. But in all the 
arms which spring from a distichal axillary the two lowest brachials 
are united by syzygy to form a double joint; and the true third 
brachial, which is also a syzygial joint, as in all Comatule, thus 
becomes the second arm-joint, as in Act. solaris”. Two formule 
are necessary for this type—one for the ten-armed form, and another 
for that with divided primary arms. The first would be 3A‘;, and 
the second “/1.2 A’. Prof. Bell, however, writes (1.2)3 At thus 
taking no account of the presence of distichal axillaries in some 
(often all) of the primary arms; and his formula also implies that 
the first, second, and third brachials of the same arm may all be 
syzygial joints, which is never the case. 
One very serious objection to Prof. Bell’s system of shorthand is 
that (except in one case) it is only applicable to those Comatule in 
which the ray-divisions are regular, 7. e. with the second and sub- 
sequent divisions all resembling the first. For regular forms like 
Act. parvicirra, Act. bennetti, and their allies, which have three disti- 
chals and three palmars with a syzygy in each axillary, Prof. Bell’s 
notation is probably as short a one as could be devised ; though it 
gives no information respecting the number of joints in each series, 
aud does not always indicate whether palmars are present or not. 
Thus, for example, his formula for Ant. articulata is V3 AY. This 
means that distichals are present but do not “present a sygygial 
joint.” It does not indicate, however, whether the axillary is the 
fourth joint (an actual case in another species), the first (which I 
have never met with), or the third, or the second (as is really the 
case). But no information is given at all respecting the presence or 
' Bull. Mus. Comp. Zool. vol. ix. no. 4, p. 10. October 1881. Were I writing 
now, I should insert the word ‘‘nearly” before “all Comatule” in the last 
sentence. 
