46 THE AMERICAN MONTHLY [Feb., 



spending surface now exposed to the wear of tides and 

 storms, it will be seen that there is at least a chance that 

 some of these ancient diatoms are mingled with our re- 

 cent gatherings ; and that it is possible that rare and cu- 

 rious finds instead of being the product of yesterday, or 

 even the blind imprint and effigy of former life, may be 

 themselves the very individual forms that once instinct 

 with life and vigor were swimming in these seas before 

 the dawn of history. 



The pond holes in the salt marsh between Silver 

 Sands, and South End were very numerous, but most of 

 them were shallow and probably dry at certain seasons, 

 and I did not find them to contain anything of special 

 interest ; but two of them just back of the beach were 

 deeper and were exceedingly rich in diatoms, Pleuro- 

 sigma balticum var. maxime being the most abundant; va- 

 rieties of Amphora and of Amphiprora were also numer- 

 ous and m^ny others similar to those that have been 

 previously described as inhabiting such locations. Actino- 

 cyclus crassus is common all along this part of the Con- 

 necticut shore, and Actinocyclus barkleyi is found here; 

 but as this marsh connects on the west with the marsh 

 bordering on Morris Creek, and as this creek is probably 

 the most prolific habitat of A. barkleyi that has ever been 

 discovered, its presence might be looked for here. A 

 living specimen of the very large Amphiprora of these 

 marshes is a remarkable object of observation. When 

 one of these diatoms pushes into the field of the micro- 

 scope, ploughing up the debris before him and filling up 

 nearly the entire field of view, and passes on sweeping 

 every thing before him ; you may possibly consider him 

 a vegetable, but never a plant. All the Pleurosigma also 

 when healthy and vigorous are very active ; almost any 

 of them are able to surpass the most rapid steamboat in 

 relative speed. For some years past I have not found 

 the beautiful red algsB that used to be abundant on these 



