448 Happon—The Actimaria of Torres Straits. 
annulata or A. tagetes, both of which species he has studied; and the same is the case 
with A. diaphana according to Hertwig (1879); but M’Murrich informs us (1889, 
Journ. Morph., p. 6, footnote) he has found in A. pallida, “a slightly developed 
muscle imbedded in the mesoglea.” Simon (1892, p. 69) describes the sphincter 
muscle of A. mutabilis as being of the diffuse endodermal type, such as is 
characteristic, for example, of the genera Actinia and Anemonia, but he gives no 
figure. He goes on to say: “‘MceMurrich hat bei einem seiner Exemplare 
von A. annulata ebenfalls Anzeichen eines schwachen diffusen Ringmuskels 
beobachtet”’ ; whereas the latter twice states that no signs of a sphincter muscle 
were observed. 
In A. mutabilis, according to Simon’s observations, there is a generalised 
sphincter, the absence of a sphincter in A. annulata and A. tagetes may be regarded 
as due to degeneration, and not as being a primitive character; this view is 
supported by the slightly developed muscle in the mesoglcea in A. pallida, since an 
incipient sphincter is always endodermal. The presence of acontia and cinclides 
also proves that these are specialised forms. 
The type species, A. Couchii, has not yet been investigated ; but as Gosse (1860, 
p. 154) says the generic appellation refers to ‘‘ its permanent expansion”; and as 
he also alludes to ‘‘ the patience with which it bore pushings, and pokings,” we 
may safely conclude that, if it has a sphincter muscle, it is very feebly developed, 
and is probably practically functionless. 
The mesenteries are in multiples of four (A. annulata), or of six. The first 
cycle of four or six pairs of mesenteries alone are perfect and are usually sterile, 
though in A. pallida and A. sp. (M*Murrich, Proc. Acad. N. Sci. Phila., 1889, 
p- 103), the mesenteries of the first cycle, with the exception of the directives are 
fertile. 
The following species may be placed under this genus, but it must be remem- 
bered that only the four species have been anatomically examined. 
A. Oouchii, Cocks; A. lacerata, Dal. (fide Andres, 1884, p. 159-—but Iam by no 
means sure of this identification; the form, I think, is A. /acerata, Dal.—one of 
the Sagartine. If this be so, Andres’ earlier name, A. comata, Andr., 1880, 
must be adopted for the Neapolitan species, as A. hyalina, D.Ch., was pre-occupied); 
A. carnea, Andr.; A. mutabilis, Grav.; A. saxicola, Andr.; A. diaphana, Rapp. ; 
A. annulata, Les. (=A. solifera, Les.: ef. M°*Murrich, 1889, Journ. Morph., p. 7); 
A. tagetes, D. & M.; A. pallida, Very. (= A. Agassizii, n.n., Andr.). 
Sub-Family.—Sacartun”,  Verrill. 
Sagartiide, with more than six pairs of perfect mesenteries, of which the six 
pairs of primary mesenteries are fertile, except the directives in some species ; body 
