283 



author, at Icasl not for any length of time', or in the extent in which it was 

 set up by Husk. With regard to the dilTerent opinions concerning this question, 

 I may refer to the discussion of it l)y Gregory^ under the title of: "The system- 

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

 that the sjjccies of Adeona and Adcoiiellopsis have hy all authors been leferrcd to 

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

 merged in Microporella. 



Synopsis of the genera. 



1) The zocrcia provideil in the central line with a single or a group 

 of connected ascopores: 



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



2) With one or several stellate ascopores Adeonellopsis (Mac Gill.) Lev. 



1) The zooccia without such median ascopores: 



U) 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 Adeonelhi (Husk) Waters. 



'6) Tlie 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, Hritish Marine Polyzoa, pag. 216, PI. XXX, ligs. 1—4. 



Adeonella insidiosa Jullien, Resultats des Campagnes scientifiques du Prince de 



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



(PI. XIV, ligs. 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 G illivi-ay (69, p. 133) originally adopted Husk's family in all its extent, while in the follow- 

 ing year (75, p. 20!)— 13) he referred Adeona and Adeonellopsis to the family Microporellidae and 

 Adeonella to Escharidac. In his last work (76, p. DO) he refers Adeonella to Schizoporellidae. * 16 a, p. 241. 



