32 THE VOYAGE OF H.M.S. CHALLENGER. 



the question in the affirmative. In the meantime, however, we have no accurate 

 anatomical studies of this most abundant Anthozoon. 



All Antheadae are easily recognised by their habit of body. As Verrill has already 

 specially remarked, the first thing which strikes the eye is the numerous, extremely long 

 tentacles, which spring from the junction of the wall and the oral disk. Their longi- 

 tudinal muscles are slightly pleated, and lie in the ectoderm, as they do also in the oral disk. 

 The circular muscle may easily be overlooked, as it is very small, and merely consists of a 

 few folds of the circular muscular layer of the wall ; hence the Antheadse are either in- 

 capable of drawing the wall over the oral disk, or can only do so slightly, and then very 

 slowly. The septa are very uniform, and the majority reach the oesophagus, so that 

 only the youngest and smallest are imperfect. Whether, as I presume, they are all fur- 

 nished with reproductive organs or not remains to be proved by further investigations, as 

 I have hitherto only examined immature animals. 



Comactis, Milne-Edwards. 



Antheadse with smooth body surface, with marginal spherules, which lie on a fold run- 

 ning outside the corona of tentacles. 



Comactis fiagettifera, Milne-Edwards (PL III. fig. 5 ; PL VI. fig. 6 ; PL VIII. fig. 9) 



Actinia flagellifera, Drayton, in Dana Explor. Exped., Zoopli., p. 126, pi. i. fig. 1, 1846. 

 Comactis flagdlif era, Milne-Edwards, Hist. d. Corall., torn. i. p. 236, 1857. 

 Comactis flagellifera, Verrill, Comni. Essex. Inst., vol. v. p. 323, 1867. 



Marginal spherules on a fold, which is separated from the tentacles by a circular 

 depression. Tentacles moderately long, with distinct terminal opening, placed in two 

 to three rows. Body discoid. 



Habitat.— Simon's Bay, Cape of Good Hope. Depth, 25 fathoms. One specimen. 



Dimensions. — Height, 0"5 cm.; breadth, l"5-2'0 cm. 



The small Actinia, which I define with some reserve as Comactis flag ell if era, came 

 from Simon's Bay, Cape of Good Hope, where it was dredged at the insignificant depth 

 of 25 fathoms. As no trace of reproductive organs could be found even on minute 

 investigation, it was, at all events, an immature animal, so that the above assertion as 

 to size cannot be considered as the standard for characterising the species. 



The wall is smooth, for although the surface in the specimen before me was re- 

 peatedly wrinkled, both transversely and longitudinally, this was plainly owing merely 

 to the high degree of contraction of the animal. There are, moreover, two very distinct 

 circular constrictions, a lower one caused by the action of the parietobasilar muscle, which 

 divides the body into two equal parts, and an upper one lying close under the tentacles, 

 and caused by the circular muscle which runs there. Outside the latter the wall- 



