F. B. Meek — Geology of the Great Pacific Railroad, 163 



The layer of fino f^ravcl beneath tlio falsc-beddctl sand was asto- 

 nishinojly rich in shells, most of which were fraj^nicntary. Scarcely 

 a handful could be taken up without ol)S(!rvin^ them. Amongst 

 them I identified the foll()win<^ : — Cardium edide (abundant), Tcllina, 

 Maclra, Mijtihis, Bnccinitm undatiim, and Tun-ilcUa tercbra. The stiff 

 clay with pebbles was scarcely less rich in shelly fraj^ments; only hero 

 the univalves were rare. It will be seen that these species are those 

 commonly found in the Middle Drift sands, and the occurrence of 

 chalk flints in such abundance, so far away from an outcrop of chalk 

 strata, indicates some long-continued and general action. 



Vn. — Geology of the Line of the Great Pacific Eailroad. 



THE following interesting communication relating to this wonder- 

 ful line of Eailway (forming part of a letter from F. B. 

 Meek, Esq., of the Geological Survey of Illinois, U.S.A., to Dr. J. 

 J. Bigsby, F.E,.S., author of the Thesaurus Siluricus), has been for- 

 warded to us for insertion by the kindness of Dr. Bigsby. 



"In regard to items of Devonian Palseontology, it so happens that 

 I have, just at this time, a few facts that may be of some interest to 

 you. Mr. Clerenee King, who has charge of a Government Geo- 

 logical Survey along the line of the Pacific Eailroad, through from 

 the Pacific, has submitted to me his whole collection of fossils for 

 examination. As the party was in the field nearly three years, the 

 collection is large, and includes fossils from various formations. 

 Consequently I am only aiming, at first, to go over the whole in a 

 general way, merely to determine the age of the rocks at various 

 localities, after which I expect to give them a more thorough study. 

 He has Devonian fossils from several localities a little east of Central 

 Nevada. From his collections, obtained in the White Pine mining 

 district, I have been able to determine that the great Silver-bearing 

 rock of those mines belongs to the Devonian; though the Carboni- 

 ferous is also well developed there. As these are very rich mines, 

 that are yielding tons of silver, I have considered it a matter of some 

 interest to determine the age of the rock. The specimens being 

 mostly imbedded in the matrix, require some time and patience in 

 order to work them out ; and more critical comparisons than I have 

 yet been able to give them, before I can speak positively in regard to 

 all of the species. I can, however, give you, without doubt, the 

 names of nearly all the genera, and of some of the species. They 

 are as follows : — 



" Corals and Poltzoa. — Diphyphyllum, Syringopora, SmitMa 

 Hennahii (Lonsdale), and Acervularia pentagona (Goldf.), or very 

 closely allied forms. Chonophyllum, very similar to C. per- 

 foliatum (Goldf.), Favosites, Alveolites, and Betepora. 



MoLLTJSCA. — Productus (small, like P. suhaculeatus) , BJiyncJionelld, 

 Atrypa reticularis (Linn.), Spirifer Utahensis (Meek),^ Spirifer Engel- 



1 I originally described this under another name {S, Norwoodi), but on finding it 

 pre-occupied, I afterwards changed it to Utahensis. [See Proceed. Philad. Acad,, 

 July, 1860, p. 308.] 



