REPORT ON THE POLYZOA. 3 



not understood, it seems that all in the group have small zooecia, a bridge over the aperture 

 ultimately forming a peristomial pore, the proximal edge of the operculum either in the 

 form of a sinus or a wide curve ; the avicularian mandibles similar, and of a type that 

 we may call Membraniporidan ; long pore tubes forming the connection both to the 

 exterior and to the neighbouring zooecia, in much the same way as in Porina coronata. 



Besides the zocecial and peristomial pores already alluded to* the pore on the front of 

 the zooecium may open into a separate chamber (PI. I. fig. 5). This I first noticed in 

 Onchopora sinclairii, and confirmed it by means of decalcified sections, and then found 

 the same occurred in a few cases of allied forms. This should be studied in living 

 specimens as the signification is not entirely clear, and it would be weU to know how 

 far post-mortem changes alter the appearance. 



The signification of the " foramina," or, as it should be called, the socket of the 

 operculum, of Cellaria, is now explained for the first time, and sections have thrown an 

 entirely new light upon the Myriozoum immersum of Busk, in which the Schizoporel- 

 lidan oral aperture is nearly at right angles to the axis of the zoarium, and thus can 

 never be seen except when dissected either by section or decalcification, so that what Mr. 

 Busk described as the oral aperture was only a cross section of the peristomial tube. 



The structure of the ovicell of Schizoporella (Gephyrophora) polymorpha, Busk, is 

 as far as I am aware unique, and is very instructive. 



Three species that I came across I have been unable to identify, and consider new ; 

 besides which, fourteen additional known species are recorded, and in a few cases additions 

 are made to the habitat. Ovicells have been seen in twenty-two cases where they were 

 unrecognised, and the form of these and other structures has sometimes made it apparent 

 that the generic or specific position must be altered. In many cases, however, Busk's 

 names are used without wishing to indicate that the forms in question have found their 

 permanent place. 



Much has lately been written about classification, and some very unfortunate and 

 premature attempts have been made at remodelling ; established genera have been re- 

 christened, and generic names given where it has been doubtful if specific were required. 

 However, when these heroic attempts are made without facts to bear them out, they are 

 usually ignored, and so bring their own punishment. As to my own position, I have 

 repeatedly stated that, as far as the Chilostomata are concerned, I consider an immense 

 advance was made when the zooecial characters were put in the first rank, and believe 

 that we are upon the right track ; but none of us can suppose that there ^•ill not be much 

 to alter as new facts are brought to light. We must not be satisfied merely with the 

 shape of the operculum, but we must give special attention to the way in which it is 

 attached and articulated, also the connection through the rosette plates ' must be more 

 studied ; fortunately many of these characters can be deciphered in dry specimens, 



• See Thalamoporella labatia, p. 13. 



