1870.] 



65 [Farlow. 



Long Island algae, ifc will be seen, are distinguished by the predomi- 

 nance of Rhodosperms. 



The coast, from New Jersey to South Carolina, is a desert as far as 

 algae are concerned. In Charleston harbor we find a few alga3, 

 principally Grateloupia Gibbesii and Delesseria hypoglossum, but when 

 we reach Key West we find a subtropical flora forming the third 

 region into which our shore is usually divided by algologists. 



Here the Fuci are wanting, and the Melanosperms are represented 

 by Sargassum and several genera of Dictyotacae. The Ehodosperms 

 are very numerous and interesting, but it is in the number and high- 

 ly organized character of the Chlorosperms that this region surpasses 

 the two previously mentioned. The Siphonaceae are numerous and 

 extremely beautiful, forming large green patches near the shore, and 

 resembling Lycopods and the larger mosses. They even have a 

 creeping subterranean stem, as the Lycopods, by which they are able 

 to remain fixed in the sand where very few algae can grow. 



Dr. Farlow closed by showing specimens and explaining the struc- 

 ture of the calcareous Chlorosperms of this region called corallines. 

 The genus Udotea and Penicillus seem to be badly limited by 

 Harvey. In Udotea flabellata we have the type of that genus. The 

 filaments here branch at their end into root-like expansions, forming 

 the surface of the frond, and the calcareous coating is uniform. In 

 Udotea conglutinata the filaments are undivided at the end, but in 

 the stipe give off lateral root-like processes and their calcareous coat- 

 ing is cribriform. In Penicillus capitatus we have a precisely similar 

 structure, except that the calcareous coating surrounds each filament, 

 while in Udotea we have it uniting the filaments into a flat frond. 

 But in Penicillus Phoenix we have the connecting link where the 

 filaments are united into plates by threes. Dr. Farlow showed a new 

 species of Udotea from Cuba nearly related to Udotea conglutinata. 



December 21, 1870. 



The President in the chair. Twenty-six persons present. 



Glacier Theory of Drift. By Dr. C. T. Jackson. 



Dr. C. T. Jackson made a few remarks on the conditions required 

 for the formation of glaciers, and explained why he had not been 

 able to adopt the glacier theory of drift phenomena. 



PROCEEDINGS B. S. N. H.— VOE. XIV. 5 JOLT, 1871. 



