1898-1902. No. 8.1 BRYOZOA. 25 



The zooecia and ooecia were thickly punctured. On the whole, 

 there seemed to me to be a close resemblance to Smitt's and Waters' 

 drawings. On some specimens from the winter haven (July 22, 1900), 

 marginal pores were distinctly visible. 



44. Porella, alba, Nordgaard, n. sp. 



PI. Ill, figs. 43-46. 



Sept. 19, 1900, off Forvisnings Valley, 2-20 fath.; July 8, 1901, 

 Ren Bay, on algae; July 12, 1901, bay at Land's End, on algae. 



Round incrustations of this species, especially on algae, were found 

 in the bay at Land's End; and at first I thought they must be Porella 

 inflata, Waters i. It proved, on a closer examination, that this idea 

 was not maintable. I now believe that the above Porella is a new spe- 

 cies, and will therefore briefly characterise it. 



The frontal wall of both the ooecia and the zooecia is finely punc- 

 tured. On boiling a colony in lye, and looking at it with the light fall- 

 ing through it, there proved to be marginal pores (fig. 43). The oral 

 aperture is oval or semicircular, and resembles that in P. acutirostris 

 rather than that in inflata. The insertions of the muscles are high 

 up on the operculum (fig. 44). The avicularium is on a prominence 

 just below the oral aperture ; and in the mandible (fig. 45), 1 < b. The 

 mandible has a „niedian lucida" as in P. inflata a character which may 

 be regarded as a connecting point of the two species. Neither in P. 

 acutirostris nor in P. alba have I found any indication of a median 

 oral denticle ; and it is therefore probable that these two species will in 

 time be removed from the genus Porella. 



45. Porella, proboscidea, Hincks. 



Syn. BiDENKAP Kat., p. 22. 

 July 15, 1902, off Havhest Mt., N. Devon, incrusting stones. 

 The ooecia are quite smooth, but the frontal wall of the zooecia is 

 much perforated, and there are often ribs and transverse bars. 



46. Porella umbonata, Nordgaard, n. sp. 



PI. Ill, figs. 40-42. 



July 22, 1900, the neighbourhood of the winter haven, incrusting 

 stones; Aug., 1900, the winter haven, incrusting stones. 



Journ. Linn. Soc, vol. 28, p. 83, PI. 10, figs. 1-5. 



