ECHINODERMATA. 
621 
organism deriving its food from the environment, but rather 
considers that it holds an intermediate relation to its host, on 
the semifluid excretions of which it may be presumed to subsist. 
This opinion, however, is by no means proven. J effreys has also 
observed that, while both Montacuta substriata and S. turtoni 
infest Echini, the former always chooses the oral, the latter the 
anal region of the shell for its abode. 
Under the name of Myriosteon higginsii, Dr. Gray describes 
an anomalous fragment which, he thinks, may indicate a new - 
group of radiated animals, nearly allied to Asterias,” and, in any 
case, a new family, Myriosteidcc. The same specimen, it had 
been previouslj'^ suggested, might represent the tail of a ray, the 
shell of a gigantic Foraminifer, or the coral of a Polyzoon. In 
truth, the proper materials for its determination seem wanting, 
but a further examination of its microscopic characters, with the 
aid of re-agents, would certainly be desirable. 
A. Agassiz describes the development of various Echinoids, 
Ophiurans, and Holothurids, comparing the early stages of their 
life-history with those of Aster acanlhion. He thus arrives at the 
conclusion that, in all Echinoderms, the young commences its ex- 
istence under the form of an open spiral star. Hence, notwith- 
standing what J. Muller has said, the apparent bilateral sym- 
metry of many of these animals is, according to our author, 
delusive, and their real plan of structure conforms to a radiate 
pattern, as already set forth by Louis Agassiz, in the third and 
fourth volumes of his ^ Contributions.^ 
CRIKOIDEA. 
Peach, C. W. On the occurrence of the Rosy Feather Star^^ 
{Comatula rosacea) on the Eastern Shores of Scotland, 
especially on that of Caithness. Proc. Roy. Phys. Soc. 
Edinb. Session 1862-63* (pp. 81-83).* 
Grube cites Alecto europcea, Leach {Comatula mediterranea, Lam.), in his 
fauna of Lossini (p. 103). 
Peach records the capture of Comatula rosacea on the eastern coast of Scot- 
land, where it appears to he much rarer than on the Atlantic shores of 
Britain. 
The question, now under discussion, whether two, or even three, species of 
Comatula frequent the British coasts requires, it need hardly be said, the 
careful examination of specimens from as many localities as possible. 
Published in November 1864. 
