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ascopore is situated pioximally to the centre of the body in a more or less devel- 

 oped depression. The primary aperture, which has no distinct hinge-teeth, is 

 almost semi-circular and bounded by a proximal, nearly straight or slightly con- 

 vex margin. The operculum (fig. 1 f) is not separated from the covering mem- 

 brane, and with the exception of a narrow marginal portion it is membranous; 

 only in old zooecia the part corresponding to the secondary aperture may be 

 slightly chitinized. The secondary aperture is of a somewhat variable, roundish 

 form, most often somewhat broader than high, and with less concave, sometimes 

 almost straight proximal margin. Each zooecium has in its distal half 14 — 16 

 uniporous rosette-plates and in its proximal half as many openings. In most corners 

 between the zooecia we find very small rounded cavities covered by a membrane, 

 which seem to be kenozooecia. 



Avicularia. A long, narrow, pointed avicularium is found in most zooecia a 

 little distally to the median pore. It is directed towards the aperture and may 

 reach some way past the proximal margin of the latter. Instead of the avicularium 

 we find in a smaller number of zooecia (fig. 1 b) an annular opening, which 

 leads into an elongated, sometimes somewhat swollen cavity. 



The gonozooecia, which are scattered singly or in groups among the zooecia, 

 are considerably larger than the latter and of an angularly oval form. Moreover 

 they differ from the ordinary zooecia by having a greater number of pores, a 

 broader, transversely oval aperture and two coalesced ascopores. The avicularium 

 is never developed, but is replaced by a cavity similar to that found in a smaller 

 number of zooecia. 



Of this species I have examined a number of colonies from Syracuse (rocky 

 and shellj' bottom, 12 — 25 fm., Dr. H. J. Hansen), which occur partly iricrusting 

 on calcareous algae, partly in free, one-layered expansions. They agree with a 

 small colony from Guernsey (Norman) also in the possession of a single ascopore 

 and of the small round kenozooecia, and as the latter thus contrary to the de- 

 scriptions of Hincks andJuUien, are not necessarily dependent on the presence 

 of a double pore, I find no reason for regarding Hincks's var. a as an inde- 

 pendent species, as Jullien does. 



Adeonella serrata n. sp. 

 (PI. XIV, figs. 2 a-2 g). 

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

 brown membrane, are generally rhomboidally vase-shaped, strongly arched and 

 provided with scattered pores. The primary aperture, which is provided with 

 well-developed hinge-teeth, has a large, well-defined, broadly rounded sinus and 



