100 



this familj'. Brettia hihceformis seems according to Hi neks' figure to have an 

 angularly bent distal wall and would therefore, according to the above given 

 synopsis, have to be referred to Gemellaria. Regarding Synnotum aviculare I have 

 no information about the structure of the distal wall, and if this, as in Gemellaria 

 loricata, is angular, there might be some ground, in spite of the presence of avi- 

 cularia, to refer it to the genus Gemellaria. A closer examination of those mem- 

 bers of the family, wliich Busk has described in the Challenger Expedition's 

 Bryozoa will no doubt lead to the setting up of several new genera, and Busk 

 explains also that to avoid doing so he made his definition of the genus Bugula 

 very elastic, whilst at the same lime dividing the species into four groups. 



It will for these species be of principal interest to find out whether they have 

 an operculum or not, and also how their distal wall and ooecia are constructed. 

 In TBugiila<i mirabilis and 'Bugula'^ leontodon, of which two species I have been 

 able to examine a small fragment without ocecia, there is an operculum as well 

 as an angular distal wall, and these together with two other species are referred 

 to Busk's first group, where the ooecia wliicli only appear in the median row 

 of the colony, are enclosed in the proximal part of the higher placed zocecium. 

 The question is therefore, whether these species form a new genus or wliether 

 they can be included under Didgmia, the ocecia of whicli however are surrounded 

 by kenozooecia. In Bugula bicornis the higher placed zocecium arises far back on 

 the basal side of the lower and meets with this in a circular disk. The form, 

 which Busk mentions under the name of Diachoris magellanica, v. distans, but 

 which he has not made the subject of any description, seems, to judge from the 

 figure given, not only to be a separate species, but also to represent a new genus. 

 The whole frontal wall seems namely to be calcified except for a median longi- 

 tudinal slit, which proximally is much widened, and in front is continued right 

 to the aperture, which is provided with a sinus. 



Bugula Oken, char, emend. 

 The zooicium without an operculum. Distal wall with a basal angular edge 

 within which there is row of uniporous rosette-plates. Freely movable capitate 

 avicalaria; free ooecia. The colonies free, branched, the zooecia in two or more 

 rows- 

 Waters as is known has shown, that an operculum is wanting in Bugula, 

 and Calvet has confirmed this observation for the French species. Whilst I am 

 certain that an operculum is absent in the other Bugula-species, which are found 

 in our Zoological Museum, I am not quite so sure of this for B. caliculata, be- 



