GEOLOGY. 299 



Coarse conglomerate containing elongated pebbles, 500 feet; slates, shales, 

 etc., 470 feet; conglomerate, 404 feet; measures concealed, 920 feet. Just 

 above these concealed measures we collected specimens of Pecopoteris affinis, 

 Brgt. (never before found in America), P. arborescens, Brgt., P. unita, Brgt., 

 Asterophyllites sublaeins, Lesqx., Annularia sphenophylloides, Brgt., Aphlebia, 

 nov. sp., SphenophyUum emarginatum, Brgt., S. Schlotheimii, Sternb., Sphertop- 

 teris, nov. sp., and Annularia fertilis, Sternb. 



Passing over about 250 feet thickness of slate, sandstones, and conglome- 

 rates, we next come to shales associated with numerous small beds of anthra- 

 cite, and containing Pecopteris nervosa, Brgt. Seventy-five feet higher in the 

 series are twenty-five feet thickness of carboniferous shales containing the 

 Alethopteris Pluckneti, Brgt., and Neuropteris tenuifolia, Brgt. The most pro- 

 ductive bed of plants is two feet thick, and is seventy feet higher yet. It 

 contains Asterophyllites sublaevis, Lesqx., Pecopteris arbor escens, Brgt., Annularia 

 fertilis, Sternb., Neuropteris, nov. sp., allied to N. Grangeri, Brgt., Lepidoden- 

 dron, Pecopteiis unita, Brgt., P. dentata, Brgt., P. cyathea (?), Brgt., Sphenop- 

 teris ekgans, Brgt., Annularia sphenophylloides, Brgt., Sphenophyllurn Schlotheimii, 

 Sternb., Cyclopteris, nov. sp., Lepidodendron dichotomum, Sternb., Sphenopteris 

 intermedia, Lesqx., Pecopteris arguta, Brgt., P. oreopteridius, Brgt., and two 

 indeterminable species of Pecopteris. This latter group corresponds to the 

 plants found at the South Salem beds of Pottsville, or the upper part of 

 No. 3 coal. The Wrentham specimens in distinction from them are from 

 the North Salem bed at Pottsville, or the lower part of No. 3 coal. 



The next five hundred feet of coal measures are mostly concealed by soil. 

 A few seams of coal have been discovered in them, which may correspond 

 with coal No. 4, as it overlies the plants of No. 3 coal. A few species of 

 plants, which are not distinctive, have been found at the top of these five 

 hundred feet of strata, immediately underlying a conglomerate of fifty feet 

 or more thickness, whose positions correspond stratigraphically with the 

 the Mahoning sandstone of the West. Above this conglomerate there are 

 1,320 feet thickness of coal measures in the town of Newport, in which no 

 seams of coal have ever been discovered. This may be due to the fact of the 

 complete alteration of these measures by metamorphic agency into silicious 

 slate, jasper, chert, serpentine, dolomite, and granite. The dolomite is in 

 two beds, one forty-five and the other sixty-five feet wide. The total thick- 

 ness of the whole system at Newport is 0497 feet. 



In the north part of Portsmouth are the only beds of coal that are worked 

 upon the whole basin, at the Aquidneck mine. In the vicinity of this 

 mine there are eleven different beds of coal. Above the beds worked for coal 

 three seams of coal have been found, and there are six below. From the 

 shale at the mine the following species of plants have been obtained : Annu- 

 laria fertilis, Sternb., Odontopteris Beardii, Brgt., Neuropteris, nov. sp., related 

 to N. Grangeri, Brgt,, Pecopteris arborescens, Brgt., Sphenopteris Gravenhorstii, 

 Brgt., and several others, not yet examined by Lesquereux. These are the 

 plants peculiar to the Lower or North Salem bed at Pottsville. 



Thus all the beds of coal and shales containing plants which we have 

 examined in the New England coal basin belong to the lower coals, and also 

 to the lower parts of the lower coals, since they all lie below the Mahoning 

 sandstone. Beds of coal (perhaps series of small beds) are found, equivalent 

 to the Pomeroy, South Salem, North Salem, and Mammoth beds, in other 

 co:d basins. AVe think it doubtful whether the beds of the upper coal meas- 

 ures of other basins are to be found in the New England coal field, partly 



