242 



CLAYSTONES. 



Wo present below several analyses of those bodies, made by Mr. Olmsted, the chemical assistant of 

 Prof. Adams. 



Carbonate of Lime, 



" of Magnesia, 

 Alumina, 

 Peroxyd of Iron, 

 Protoxyd of Manganese, 

 Silica, 

 Water, 



These concretions occur in Europe, and some years ago we analyzed a few from Sweden, with the follow- 

 ing results : 



1st Specimen. 2d Specimen. 



Carbonate of Lime, . . . 60.33 61.26 



Carbonate of Magnesia, . . . trace 1.40 



Silica, Alumina, Iron, &c., . . 35.20 32.20 



Water, 2.67 3.44 



These are certainly of essentially the same nature as the Vermont claystones, though containing more of 

 carbonate of lime. Yet sometime ago " the Swedish scientific men believed them to be something of or- 

 ganic remains ; some sort of mollusks, which were more or less wrapt in a mantle." They would abandon 

 such an opinion were they to examine a collection of Vermont claystones. 



Prof. Adams deposited nearly 900 specimens of these concretions in the State Cabinet, from the follow- 

 ing towns : Sharon, Pittsford, Bethel, Charlotte, Montpelier, Brandon, Sudbury, Weybridge, Colchester, 

 Mallet's Bay, Norwich, Orwell, Burlington (Appletree Bay), Ryegate, Shoreham (Larrabee's Point), 

 Rutland, and Stowe. We have found several other localities noticed in the catalogue of rocks appended 

 to our Report. 



We have not found time to collect specimens anew, from the localities described by others ; yet we 

 have had access to the splendid collection presented by Prof. Adams to Amherst College, amounting to 

 over 900 specimens, and from them have selected enough of the most peculiar forms to occupy Plates IX, 

 X, & XI. Gladly would we give sketches of hundreds more, many of whose forms are very remarkable. 

 But although the subject be a very curious one, we do not feel justified in giving more figures. The 

 following are all which we present. 



PLATE IX. NOB. 16 to 23 are spheres. 



Nos. 1 to 15, and 24 to 29, are flattened spheres with rings or thick belts upon their margins. 



No. 30 is flat but made up of numerous flattened rings firmly united. 



Nos. 31, 34 and 35 are compounded with several smaller plates, upon a common plate. 



No. 33 is a smooth plate with occasional nearly hemispheric bosses, which are usually hollow within, and 

 the plate beneath is perforated. Probably the surface represented, is the under side. One of the bosses 

 has a slit in it. 



No. 36 is very thin, but shows numerous united flattened rings. 



No. 37 looks like a dressed doll, or heathen image. 



Nos. 38 to 44 are flat, with outer rings. 



Nos. 45 and 46 are prolate spheroids. 



Nos. 47, 51 and 52 are flat, showing two centers of attraction or formation, with a connecting strip. 



Nos. 48, 49 and 50 are flat, with numerous belts, quite irregular. 



No. 53 is a congeries of spheroids. 



