Brj'ozoa. 465 



As a rule a median avicularium is found in every zooecium, and 

 takes up more than 1луо thirds, not rarely three fourths, of its whole 

 length. It consists of two portions of different breadth, \vhich are, 

 however, not sharply separated from each other, namely a broader 

 distal portion, which, when regarded from the frontal surface, is 

 elongate ovate, and a more narrow proximal part which has about 

 the same breadth through the whole of its length. The former, the 

 terminal face of which represents the avicularian area is obliquely 

 ascending, and its greatly projecting distal half which almost com- 

 pletely conceals the aperture, when regarded from the frontal sur- 

 face, is on each side connected with the zooecium by means of a 

 triangular calcareous plate, the free margin of which on each side 

 reaches from a point a little distally to and outside of the hinge- 

 tooth to a point not far from the avicularian area. The prox- 

 imal portion, which is of very different breadth, is provided with a 

 pore placed a little distally to its rounded end, but not rarely it is 

 in a larger or shorter portion of its length divided into two, each of 

 which is provided with its own pore. 



The colonies are two-layered wdth compressed branches, some- 

 times bifurcate. 



Of this species some very young colonies and some fragments 

 of older ones have been found. 



St. 63, Stormbugt, 20— 40 m. 



St. 95 a, The Sound between Renskæret and Maatten, 50 — 100 m. 



Porella princeps Norman. 



Monoporella spinulifera, var. præclara, Hincks, Ann. Nat. Hist. ser. 6, 



Vol. IX, p. 152, PI. VIII, fig. 3. 

 Porella princeps Norman, Ann. Nat. Hist. ser. 7, Vol. XII, p. 114, PI. 

 IX, figs. 8—11. 



Of this species I have only seen a small young colony with a 

 diameter of c. 9 mm. I have not seen a single avicularium. A 

 number of the zooecia are provided with a broad but very low rect- 

 angular median tooth. The ooecia which are not yet covered are 

 very convex, a little longer than broad and provided with a more 

 or less distinct median ridge. 



On a stone. 



St. 71 a, off Cape Bismarck, 30 — 40 m. 



Porella proboscidea Hincks. 



The small colony examined differs from those described by 

 Hincks in the lack of the coslæ. The surface is granular and the 

 ooecium, the ectoooecium of which is perforated by a small fissure, 



35* 



