REPOET ON THE ACTINIARIA. 83 



The tentacles are small, broad at the base, and pointed towards the end ; they are 

 placed in three rows, as they probably alternate in the first and second row, whilst the 

 third row contains double the number. Their longitudinal muscles are ectodermal and only 

 slightly pleated. 



The oesophagus and the two oesophageal grooves are of a deep brown-violet colour 

 even in the spirit material ; this is caused by fine pigment granules deposited in the 

 ectodermal epithelium. 



There are altogether four cycles of septa. Only the septa of the first order are 

 perfect, all the others are imperfect, but, on the other hand, the latter only bear (male) 

 reproductive organs, whilst the former are sterile. 



The muscles of the septa are very strong, as Jourdan already observed in Phellia 

 elongafa ; in the first three cycles especially the longitudinal muscles form mushroom- 

 shaped projections in the middle of each septum, which show the delicate, dendritic 

 figures of a repeatedly folded muscular lamella in transverse section. The transverse 

 muscular layer is also thickly pleated, so that it is doubly remarkable that I could find 

 no trace of a parietobasilar muscle even in sections. 



All the septa seem to bear acontia ; these are extremely fine, and lie coiled in the 

 lowest section of the gastric space. I was able to make them out distinctly in transverse 

 section, but, on the other hand, I could not find any openings in the wall. 



The directive septa were fused by the free margins, nearly their entire length below 

 the oesophagus (PI. VIII. fig. 2). I only examined one pair of them, as I wished to 

 destroy the siugle specimen taken by the Challenger as little as possible. The longi- 

 tudinal muscles of one septum pass continuously into the longitudinal muscles of the 

 other, whilst a mesenteric filament is wanting at the point of junction. The filament 

 is confined to the short space lying between the lower margin of the oesophagus and the 

 beginning of the fusion, where it is coiled in numerous curves. I shall leave it an open 

 question whether it be correct to speak of a fusion of the free margins, as I have done for 

 the sake of simplicity, or whether the union of the two septa does not rather represent a 

 more primitive condition. I wish, however, to draw attention to one fact which seems to 

 favour the latter view, and which I have formerly noticed repeatedly, viz., that in the 

 young Actiniae we frequently find the newly-formed septa of a pair connected together 

 in the same manner as in the principal septa of Phellia and the secondary septa of 

 Tealia bunodi/ormis, figured by me in Plate VIII. From this it would appear that 

 separation takes place later on, as at a later period all the septa have free margins set 

 with mesenteric filaments. 



Bunodes, Gosse. 



Sagartidse (?) with numerous papillse on the wall, which are placed in regular 

 longitudinal rows, corresponding to the intraseptal spaces. 



