209 



Danw, in which there is a similar relation hctween areas and zocecia as in M. 

 (labia. Ooecia appear to he found only in B. Elea & B. eclunala, and they are 

 here more consjiicuous on the surface of the colony than in M. diibia. In the 

 former they appear to have a trilohed opening like the one found in Busk's 

 species. A fossil species, which may also with certainty be referred to this familj', 

 is Bifliistra Prazaki Novak'. As the author gives not only a transverse section of 

 a colony hut also figures the basal aspect of an isolated zoa'cial layer we here 

 see a distinct contrast between the broad, rhombic areas and the long, narrow, 

 hexagonal zocecia. Until a closer examination has settled the question whetlier 

 these species sliould he referred to one or to several genera we suggest that they 

 be all referred to the genus MetubranicclUui<i. 



Family Cellulariidae' (non Hincks). 

 Cellariidae Hincks. 

 Salicornariadae Busk. 

 (I'ls. VII .>;: VIII). 



The whole frontal wall of the zocecia is a cryptocyst and they have a well 

 chitinized, hilaminar, simple operculum with a straiglit or concave proximal 

 margin. Within the jjroximal and sometimes also within the distal margin of the 

 aperture is placed a pair of (or sometimes a single broad) supj)orting teeth. 



The ou'cia are iiollow spaces in the thick frontal wall and arise by a resorp- 

 tion of the latter, which they finally break through. The suhopercular area of 

 the avicularia has an unusually strongly developed, sometimes almost complete 

 cryptocyst. Tlie colonies are most frequently jointed with cylindrical internodes, 

 more seldom two-layered lamina'. 



The depressed, rhombic or hexagonal areas are not only separated by the 

 raised borders, in which the more or less sharply ascending lateral parts meet, 

 but also by the distinct furrows which run along the middle of these borders. 

 The aperture sunounded by a somewhat projecting margin is most fretpiently 

 situated in or proximally to the distal third of the area, more seldom in its 

 centre, and it is most often furnished with a more or less convex, more rarely 

 straiglit j)roxinial margin, which has generally sliort, rounded, conical, more 

 seldom long and pointed teeth supporting the operculum. In a few cases a couple 

 of similar teeth are also found in the distal margin of the aperture. The crypto- 

 cyst is more or less tui)erculous and in a number of species (for instance in 

 Cell, divaricala. Cell, diihid) it has within each area two long, curved, elevated 



* 85, p. 94, T:if. Ill, fins. '20—25. ' As to tlic use of the- iuiiir- C.cllulniiidae sec- 83, p. 577—78. 



U 



