with some Notices of American DiatomcB. 119 



hundred square yards in extent, which is wholly made up of the 

 siliceous shells of the BadllaricB, Sfc. in a fossil state. 



This deposit is about a foot below the surface of a small peat- 

 bog, immediately at the foot of the southern escarpment of the 

 hill on which the celebrated Fort Putnam stands. In draining 

 this bog, a large ditch was dug, and among the matter thrown 

 out, my attention was attracted by a very light, white or clay 

 colored substance, which when examined closely in the sun-shine, 

 showed minute glimmering linear particles. On submitting it 

 to observation, by means of a good microscope, I found it to be 

 almost entirely composed of fossil Infusoria, with occasionally a 

 few fragments of a Diatoma or Fragillaria. 



I have since examined many specimens, taken from different 

 and distant parts of the same bog, and have invariably found 

 the same siliceous bodies, and in the same abundance. 



There can be no doubt that in this place there are several tons 

 of the shells of beings so minute as to be barely visible as brilliant 

 specks, when carefully observed in a strong light by the naked 

 eye. Hundreds of years must have elapsed before such an accu- 

 mulation could have been made. 



The forms most abundant in this peat-earth are represented on 

 Plate 3. Fig. 1, represents one of the Bacillarias, which is appar- 

 ently identical with fossil specimens from Ehrenberg. Fig. 2, 

 represents a boat-shaped shell, which like the preceding is marked 

 with parallel lines of almost inconceivable fineness. Fig. 3, shows 

 a smooth siliceous body whose nature is to me unknown. Fig. 

 4, is a rough siliceous body of whose nature I am also ignorant. 

 With these occur great quantities of exceedingly smalL rings, 

 discs, and spheres, see Fig. 11, Plate 3. 



All these forms together compose a white or clay colored mass, 

 which when dry feels very light, does not effervesce or dissolve 

 in acids, and is not fused by the blov/-pipe. I have no doubt 

 that this substance will be found abundantly in many peat-bogs, 

 and I hope in the next number of this Journal to see the announce- 

 ment of its discovery in many localities.* From its white color, 



* Since writing the above, I received from my scientific friend, O. Mason, Esq., 

 President of tiie Providence Franklin Society, a letter from which I take the liberty 

 to extract the following. He says, " your microscopic examinations of the white sub- 

 stance occasionally found at the bottom of peat-bogs have afforded a satisfactory and 

 very curious solution of a phenomenon which has often occupied my mind. I could 



