283 



author, at least not for any length of timeS or in the extent m which it was 

 set up by Busk. With regard to the different opinions concerning this question, 

 I may refer to the discussion of it by Gregory ^ under the title of: .The system- 

 atic position of the Adeonellidae'^, and I may here confine myself to the remark, 

 that the species of Adeona and Adeonellopsis have by all authors been referred to 

 the family Microporellidae, the two genera being sometimes retained, sometimes 

 merged in Microporella. 



Synopsis of the genera. 



1) The zooecia provided in the central line with a single or a group 

 of connected ascopores: 



2) With one or two simple ascopores Adeona (Lamour.). 



2) With one or several stellate ascopores Adeonellopsis {UdiC Gill.) Lev. 



1) The zooecia without such median ascopores: 



3) The proximal part of the secondary aperture, which appears 

 sooner or later, is transformed by a coalescence of two calcareous pro- 

 cesses into a pore, which leads into the space between the primary 



and the secondary aperture Adeonella (Busk) Waters. 



3) The proximal part of the secondary aperture is not transformed 

 into a pore Bracebridgia Mac Gill. 



In the above synopsis no regard has been paid to the form of the primary 

 aperture or the structure of the operculum, for the reason, that the form of the 

 primary aperture, to judge from the relatively small number of species examined 

 in this respect, is subject to rather great variation within the separate genera. 



Adeona violacea Johnston. 



Microporella violacea Hincks, British Marine Polyzoa, pag. 216, PI. XXX, figs. 1—4. 



Adeonella insidiosa Jullien, Resultats des Campagnes scientifiques du Prince de 



Monaco, fascicule XXIII, Bryozoaires, 1903, pag. 54, PI. VI, fig. 4. 



(PI. XIV, figs. 1 a-1 g). 



The zooecia, the finely tuberculated surface of which is covered by a black, 

 strongly iridescent membrane, are elongated, hexagonal and provided with rather 

 numerous pores, which are most closely situated in the marginal portion. The 



' Mac Gillivray (69, p. 133) originally adopted Busk's family in all its extent, while in the follow- 

 ing year (75, p. 209 — 13) he referred Adeona and Adeonellopsis to the family Microporellidae and 

 Adeonella to Escharidae. In his last work (76, p. 90) he refers Adeonella to Schizoporellidae. ^ 16 a, p. 241. 



