345 



For the rest, all the species mentioned here will be made the object of more 

 detailed investigation in a later work on the Bryozoa material of the Ingolf Ex- 

 pedition. 



Family Celleporidae, char, emend. 

 Celleporidae Busk, Hincks, part. 



No spines. The aperture as a rule circular with a broader or narrower, more 

 or less sharply marked off sinus, more rarely with a simple, concave, proximal 

 margin. Hinge-teeth may be absent or present. The operculum is always dis- 

 tinctly marked off from the compensation-sac, well-chitinized as a rule and pro- 

 vided with two muscular dots. A peristome more or less developed present as a 

 rule. Avicularia seem to be always present, and in most species a more or less 

 strongly projecting, almost always asymmetrically placed avicularium is present 

 proximally to the aperture. Further, large scattered avicularia often occur. The 

 hyperstomial ocecia are free and the ectoocecium is wholly or partially calcified. 

 The basal zocecia have a rhombic circumference and their distal half is as a 

 rule provided with a number (ca. 8) of adjoining, uniporous or few-pored pore- 

 chambers, more rarely with few, widely separated pore-canals. The colonies, 

 which are encrusting or freely branched, as a rule show superficial budding, and 

 the zocecia are often more or less erect. 



The aperture is provided as a rule with a sinus, the dimensions of which are 

 subject to very considerable variation, as can be seen, for example, from the 

 figures of the aperture and operculum given by Busk^ Whilst the opercular 

 tongue and the sinus are in some species very narrow and sharply marked, in 

 others the latter is broadly rounded and so faintly marked, that there is a plain 

 transition to the almost quite circular aperture which is found in a smaller 

 number of species, e. g. in Cellepora pumicosa and Cell. (Lagenipord) socialis. The 

 form of the aperture seems therefore not available as a generic character and the 

 same is also the case apparently with the peristome, which is sometimes devel- 

 oped to a very varj'ing extent in the same species, e. g. in C. Costazzi. As the 

 majority of the members of this family show superficial budding, the rosette- 

 plates only appear on the zocecia in the basal layer of the colony, and in the 

 large majority of the species I have been able to examine, each zocecium in its 

 distal half shows a number of juxtaposed uniporous or few-pored pore-chambers, 

 which are apparent through the basal wall when the colony is loosened from 

 its under-layer. In two species, which occur in very small colonies, namely, in 



' 8, PI. XXX and XXXVI. 



