468 



SUPPLEMENT. 



R. of Foi-tli to forty fms. deep sea, and fifty fras. off Troup head, 

 Aberdeenshire. 



Halecium halecinum— four fms., eight fms., Est. of Thames, four 

 fms. Coast of Suffolk, eight fms. Wold, Coast of Norfolk, in fine 

 perfection in March 1846. Thirty-five fms. Coast of Yorkshire 

 and Northumberland, April 1845, with ovaries, Est. of Forth, 

 Aberdeenshire. Thirty-five fms. Copinsha, Ork. Isds., May 

 1845, without ovaries. From these observations it would 

 follow, that those individuals which inhabit shallow water, 

 spawn before those in the deep sea. 



Sertularia poltzonias— fifteen fms. Dimlington, thirty-five fms. 

 Huntly Foot, April 1845. Thirty -five fms. off Copinsha, May 

 1845, all without ovaries ; but it was found littoral in Papa 

 Westra, Ork., with ovaries, in August 1845. All littoral indi- 

 viduals or species must be " forced " exceedingly, for when the 

 sun is out upon a summer's day, the water in the pools left by 

 the receding tide, becomes almost hot enough to boil them. 



Sertularia rttgosa— fifteen fms. Dimlington, two species, unless all 

 the cells occasionally become developed into ovaries. All my 

 specimens have the cells distant and without ovaries. Orkney, 

 &c.. May and April, except one, in which the cells are crowded, 

 and have the cells *? three times larger than is usual. 



Sertularia rosacea— this species is always found by dredging from 

 Thames to Orkney, but presenting some difference of habit; 

 those from the Southward being more opaque and erect than 

 those from deep water from the Northward ; in short, the 

 Southern kinds are corneous, the Northern membranaceous. 



Fig. 83. 



In the latter, the walls of the cell induplicate, <tc. The ovary 

 (Fig. 83) presents a very different appearance at different stages 



