1876.] 47 [Farlow. 



groups as has marked the investigation of these lake-basins by 

 Brusina, Neumayr, Meek, Stimpson and others, is likely, unless au- 

 thors investigate closely the work of their predecessors in similar 

 fields, to cause a great deal of confusion. It will be a great gain to 

 science when every investigator recognizes it as his duty, not only 

 to elucidate the physiological or anatomical features of a species, but 

 to use at least ordinary care in giving its proper binomial designa- 

 tion, or failing in that, at least to refrain from adding to the already 

 overwhelming mass of zoological synonymy. 



Dr. W. G. Farlow made some remarks on certain algae 

 which were found, in August, 1876, in Horn Pond, Woburn, 

 and which had caused a very disagreeable odor, resembling 

 that of a pig-pen. 



The pri ncipal species causing the trouble was so far decayed that 

 it was impossible to determine it specifically, but it seemed to belong 

 to the genus Anabaena, and was perhaps related to Nodularia litorea 

 Thuret, which produced at one time a similar odor at Deauville near 

 Cherbourg. Another alga, Plectonema Wollei Farlow, vulgarly 

 called eel-grass, was found at the same time, and also a quantity of 

 Clathrocystis aeruginosa Henfrey. The former plant is one of the 

 Nostochineae, and when it decays has also a pig-pen odor like that of 

 the Anabaena previously mentioned. The Clathrocystis, known in 

 Germany as the Wasserbliithe, is now considered to belong to the 

 group of Bacteria, and is closely related to Clathrocystis rosea-persi- 

 cina found on the decaying algae of our sea shore. 



Dr. Farlow then gave a short account of what is known of the 

 development of Clathrocystis and some of the Bacteria and Nosto- 

 chineae, and described the peculiar effect which the species of Beg- 

 giatoa have in producing sulphurous odors. 



General Meeting. December 20, 1876. 



The President, Mr. T. T. Bouve, in the chair. Forty per- 

 sons present. 



The following papers were read : — 



Some Remarkable Gravel Ridges in the Merrimack Val- 

 ley (Abstract). By George F. Wright. 

 A formation of gravel, known at Andover as "Indian Ridge," has 

 long been familiar to the citizens, and has been remarked upon fre- 



