6 PALAEONTOLOGY. 



fiiriiisli ovGii a strono-er arg-iinient ag'ainst tlie conclu.sion that this formation 

 might belong to the Carboniferous. Hence we cannot doubt that these beds 

 belong to the Devonian, and probably to about the horizon of the Hamilton 

 Gronp of the New York series.* Indeed, in 18G0, on nearly the same evi- 

 dence, this formation, at localities a little farther north, was referred by the 

 writer to the Devonian, from the examination of specimens brought from 

 there by Colonel Simpson; though at that time this rock was not known to 

 contain silver-mines, f 



The little Proetus, illustrated by fig. 10 on plate 1, probaljly also came 

 from near the same horizon as the Devonian fo.ssils mentioned above, as it 

 is contained in a similar matrix quite unlike that containing the Piilon Range 

 fossils. 



On the lower part of plate 3, a few fossils are figured together in a sepa- 

 rate division, because they are of a somewhat doubtful nature. They are 

 also from the White Pine District, and came from beds known to hold a 

 position between well-marked Carboniferous and Devonian rocks. All of 

 them, excepting the Spirifer, came from a black bituminous shale, asso- 

 ciated with some more or less arenaceous beds, beneath well-marked Car- 

 boniferous limestones. The Aviculopecten (fig. 10) is very closely allied to 

 some western Carboniferous forms; and the little shell represented by fig. 8 

 also resembles Carboniferous species believed to be at least nearly related 

 to Posidonomya. The Brachiopod represented by fig. 9, however, is remark- 

 ably like Devonian species of Lciorhjnclius, and hence would favor the 

 02)inion that this shale is Devonian. The Sp'mfer represented by fig. 11 

 seems to belong to the common and widely-distributed Carboniferous species 

 S. cuspidahts, and came from a gray, subcrystalline, cherty limestone, above 

 the above-mentioned black slate, and was associated with some large Crinoid 

 cohuuns, casts of an Orthis, like 0. resiipinata or 0. MicheUm, and imperfect 

 specimens of a smaller Spirifer, apparently like the Devonian species S. 



•Tlu'se, riMiiiirks on the Devoiiiati ago of the Wbite Pine ^silver-bearillg rocks 

 were quoted l.y Mr. Aruol.l Hague, in the Mining Peport of Mr. King's Survey, 410, 

 (is,sueil in 1870.) It is to be regretted, iiowever, that, owing to the fact thati^fr. Ilaguo 

 did not see tlie proof, several annoying typographical errors, in the names of the 

 lossils mentioned, were not corrected.— P. P. AL, Sei)t. 29, 1S74. 



tSee Proceed. Acad. Nat. Sci. Philail., ISGO, XII. 



