208 ANNUAL OF SCIENTIFIC DISCOVERY. 



coal have been found to be distinguished from one another by the peculiar 

 forms of vegetation associated with them. Each series of beds has asso- 

 ciated with it either characteristic species of plants, or, more usually, differ- 

 ent species, common to several series of beds, but grouped together in a 

 peculiar way. 



In the Appalachian and the Western coal-fields the synchronism of the 

 different beds has been largely ascertained, and the equivalency is satis- 

 factory. 



The equivalency of the New England beds of coal with the others has 

 never till now been ascertained. We have made collections of plants from 

 several localities in the New England basin, and Mr. Lesquereux finds that 

 their distribution corresponds to that of the beds in the other basins. The 

 localities examined are in Wrentham, Mass., Valley Falls, Portsmouth, and 

 Newport, R. I. 



From Wrentham the following species were obtained : AsteropJtyUites lan- 

 ceolata, Lesqx., A equisetifarmis, Brgt., Annularia longifolia, Brgt., SpJif.no- 

 plnjllnm Schlothefmii, Brgt., Calamites Suckowii, Brgt., C. Cistii, Brgt., Neu- 

 roptc-ris jlexuosa, Brgt., N. Jiirsuta, Lesqx., N. Loschii, Brgt., Alethopteris 

 Pennsylvanica, Lesqx., A. nervosa, Gopp., Pecopteris Mitoni, Brgt., P. arbo- 

 rescens, Brgt., Sphenopteris abbreviate., Lesqx., Lepidophyttum, nov. sp., Trigo- 

 nocarpum, nov. sp. Lesquereux says of the locality of these plants : " The 

 exact geological horizon of the shales where these species of fossil plants 

 have been collected is obvious, not only from the species themselves, but 

 also from their relation in number to each other. It corresponds with the 

 shales covering over No. 3 coal of the Western sections of the coal measures, 

 equivalent of coal D. (Lower Freeport) of J. P. Lesley's 'Manual of Coal.' 



"The exact counterpart of your shales (or exact likeness) is found espe- 

 cially at both the Salem beds of Pottsville, at W. W. Wood, Port Carbon, 

 and many other places of the anthracite basins of Pennsylvania ; and in the 

 Western coal measures, in Kentucky, along the Tug river (separating Ken- 

 tuck}' from Virginia), in Greenup, Lawrence, Breathitt counties, etc. In the 

 Western coal-fields of Kentucky and of Illinois, this bed is frequent!}' found 

 with the same fossils, and it is one of the best and most reliable for its coal. 

 In the East, this bed is generally separated into two or three different beds 

 by clay partings of various thicknesses, each bed of clay containing the 

 same or nearly the same plants. It often runs to No. 4, from which in the 

 Western coal-fields it is separated by a limestone, and to which it is related 

 by its vegetation, or the ferns." 



These shales in Wrentham lie above a bed of coal which has been worked, 

 at least a hundred feet; and probably the bed which was worked in Mans- 

 field and other adjacent towns is at the same geological horizon. The plants 

 from these beds were not examined, but the probability is, as suggested by 

 Lesquereux before he knew of its relative position, that this workable bed is 

 the equivalent of No. 1 B, the big or mammoth coal bed of the East. This 

 is confirmed by the early discovery of stigmarice at the lower Wrentham 

 bed, and in Mansfield. 



The general position of the Valley Falls bed is the same with that just 

 described. We did not obtain a sufficient number of plants from its shales 

 to authorize a certain conclusion from them. 



We- have made a careful examination of the island of Rhode Island, par- 

 ticularly its southern part, and the following is the order of strata, com- 

 mencing at the base of the carboniferous system and proceeding upwards : 



