456 Hapvpon—The Actiniaria of Torres Straits. 
included in it Metridium, Adamsia, Calliactis, Stelidiactis, and Aiptasia, and 
thinks that Paraphellia should be placed here too. The genus Aiptasia must be 
separated from it, as it constitutes the type of a sub-family of Sagartids; and the 
genus Mitactis, Hadd. and Duerd., should be added to it, and I regard the genus 
Paraphellia as belonging to the next sub-family. 
METRIDIUM, Oken (Actinoloba, Blainy.). 
Metridiinze with a smooth body-wall and numerous tentacles, which extend 
over nearly the whole of the oral disk, which is greatly expanded and frilled; the 
upper border of the column is swollen to form a thickened ring, above which is the 
delicate capitulum. 
M. dianthus (Ellis), WM. marginatum (Les.), M. fimbriatum (Verr.), M. reticulatum 
(Dana). 
MITACTIS, Hadd. and Duerd.* 
Metridiinee with a smooth body-wall; oral disk of not much greater diameter 
than the column ; tentacles short, marginal in three or four cycles. 
M. Australie, H. & D.; MW. similis, H. & D. 
ADAMSIA, Forbes. 
Metridiidze, with cinclides arranged in from one to several horizontal rows 
towards the base of the column; no verrucee; column short, base extended into 
two broad lateral lobes, clasping a gastropod shell inhabited by a hermit crab, 
the lobes unite where they come in contact, giving the body an annular form ; 
the pedal disk secretes a tough cuticle; tentacles short. 
This genus was erected by Forbes (Ann, Mag. Nat. Hist. v., 1840, p. 181) 
for A. palliata, Boh. (or A. maculata, Adams, as he called it). 
CALLIACTIS, Verr. 
Metridiidee, with prominent cinclides, arranged in from one to several hori- 
zontal rows towards the base of the column; no verruce ; column very change- 
able in form, in full expansion elevated, sub-cylindrical, with a broadly expanded 
base, in contraction forming « low, flattened cone or convex disk; basal margin 
* Trans. R. D. S. (2), v1.,[1896, p. 162. 
