BY WILLIAM A. HASWELL, M.A., B.S.C. G09 



always cliaracterisecl by the presence of a deep cylindrical pore 

 running in the direction of the axis, but not quite reaching to the 

 opposite pole. This pit is always well-defined and uniformly 

 cylindrical, and it is difficult to explain its nature unless we 

 suppose that it was occupied by a minute Actinid similar to those 

 already described. ]S'one of the specimens which I have seen 

 exceeded an eighth of an inch in diameter, and most of them, 

 from their worn appearance, must have been dead when dred^-ed, 

 so that there would seem to be a tendency in this species to airest 

 of growth and death at a certain definite stage of growth. This 

 species, it is to be remarked, differs entirely in the nature of its 

 zooecia from the branching species already mentioned, which is 

 a normal Cellepora. 



A species very nearly related in the peculiar form of the cells 

 of C. fossa was dredged off Port Stephens, at depths of 20 to 30 

 fathoms. The form of the bryozoarium in this case is usually 

 that of an elongated cone, a third of an inch to half an inch in 

 length, with a pit, exactly like that occurring in C. fossa, in the 

 centre of the base ; but sometimes it has the form of a circular 

 plano-convex disk, a third of an inch in diameter, with cells on 

 both sides and without a pit, while in other cases the shape is 

 more irregular, subhemispherical or the like, but never larger 

 than a pea. 



It seems very likely that the first-mentioned species starts from 

 an early stage resembling C. fossa or its ally, a group of cells sur- 

 rounding a single young Actinid ; as the zoarium increases and 

 the cells grow round the mouth of the cavity occupied by the 

 latter, the canal is constantly being elongated as the sea-anemone 

 remains at its orifice, and thus prevents it from being encroached 

 upon by the multiplying cells. Sometimes the sea-anemone* gives 

 off a lateral bud, and at this point the canal is seen to branch, 



* I sent specimens of the Actinid to Prof. Mosely of Oxford, who will 

 describe them. 



