BOTANY, CONCHOLOGY, AND GEOLOGY. 35 



come to those most beautiful phenomena of our shores, 

 the physalioe, which in their more minute form cause 

 the beautiful phosphorescence on the waters. Indi- 

 vidual specimens, large and highly colored, are some- 

 times found upon our western beaches. Though these 

 " Portugese men-of-war " seldom visit our latitudes in 

 their full beauty, — driven here as they are after a 

 storm, consequently much torn and dilapidated, — yet 

 one of the finest specimens known to the American 

 coast was found at Nantucket in a perfect state a few 

 years ago. The whole shore being strewn with others 

 more or less imperfect, gave the beach the appearance 

 of a rainbow; their surfaces, as every one knows, hav- 

 ing the capacity of polarizing the light. 



As these zoophytes are a connecting link between 

 the shells of the sea and plants, aquatic and others, 

 we cannot pass on to the latter without a few words 

 upon the sea-weeds. In no part of the Northern 

 United States are the hues of the ulva found so bright 

 and so varied as upon our own shores. While we have 

 the plumula, the corallina, and many other genera of 

 alga? in their usual beauty, the species of the ulva 

 especially the olive, have a much deeper tint. Some 

 thirty years ago an entirely new species of the ecto- 

 carpus was discovered . on the north beach of this 

 island, of which a very good illustration (colored) is 

 to be found in some one of the earlier reports of the 

 Smithsonian Institute. 



Leaving the sea-weeds without further comment, we 

 come to that branch of natural science which interests 

 the old and young, the student and the florist; viz., the 



