GALENA LIMESTONE. 313 



The Big Suamico river has likewise denuded this formation at a few points. The most 

 noteworthy of these is at Flintville, and as the section here best illustrates the peculi- 

 arities which the formation has assumed, it may be described in some detail. 



1. The lowest rock seen is a bed of soft, bluish-green, disintegrating shale, only par- 

 tially exposed. 



2. Above this, is a three-inch layer of coarse, blue, granular, half crystalline limestone, 

 mixed with earthy, argillaceous material, and at all points very full of Orthis testud'maria. 



3. Upon this, rest 10 inches of soft, bluish-green, decomposed shale, containing nurn- 

 ulitic forms of Chcetetes and Streptelasma corniculum. 



4. Above this, lies a four- inch bed of dep blue, coarse-grained, crystalline magnesian 

 limestone, mixed with more or less of yellowish, earthy matter, the whole having a high 

 specific gravity. This layer is characterized by the presence in unusual numbers of 

 Receptaculites Oweni, the characteristic fossil of the Galena limestone, while other fossils, 

 except minute crinoidal discs, are rare. 



5. Upon this, repose 2 feet 10 inches of shale and impure limestone, easily decompos- 

 ing on exposure, and containing many branching forms of Chcetetes, Streptelasma cor- 

 niculum, Orthifi lynx, 0.j)licatellaiLeptcena sericea, and other fossils. 



6. Next above, occurs a 10 inch layer, similar to No. 4, but more massive, and marked 

 by irregular laminae of a dark, dirty greenish, argillaceous, and apparently carbonaceous 

 material, giving a somewhat fetid odor under the stroke of the hammer. 



7. Five inches soft shale, similar to No. 3. 



8. A four-inch layer, similar to No. 5, but more markedly blue. 



9. An irregular layer, about 2 inches thick, that is little else than a mass of the stems 

 of the branching Chcetetes. The numulitic forms, as also Brachiopoih and Trilobites, are 

 present. 



10. About 1 foot 6 inches of shale, containing Chcetetes in abundance, especially the 

 more hemispherical forms. 



11. Above this, lie about 3 feet of thick bedded, massive dolomite, very similar to that 

 previously described at Kaukauna and Duck Creek. It contains Receptaculites Oweni, 

 besides Orthis plicatella, 0. lynx, Leptcena sericea, Strophomena alternata, Raphistonict 

 lenticularis, and fragments of trilobites and crinoids. 



The entire collection made at this locality, which is given below, shows an interesting 

 mingling of those species that are characteristic of the Galena limestone in its typical 

 localities, with an abundant Trenton fauna not found at this horizon in the Lead region. 

 Cruziana ? Receptaculites Oweni, Chcetetes lycoperdon, and three new species, Strepte- 

 lasma corniculum, two new species of Stictopora, Lingula attenuata ? Philodops truncata, 

 Orthis lynx, 0. plicatella, and a form with bifurcating ribs like 0. fissicosta, 0. testudl- 

 naria, Hemipronites Americanus, n. sp., Strophomena alternata, S. incrassata ? Lep- 

 tcena sericea, Zygospira recurvirostris, a new species of Rhynchonella, Pentamerus 

 (Camerdla?) hemiplicatus, Raphistoma lenticularis, Murchisonia bellicincta (slender 

 form), Murchisonia (slender form like M. gracilis, round volutions), Fusispira elongata, 

 Bellerop}ion bilobatus, Cyrtolites Di/eri, Endoceras proteiforme, Illcenus taurus, I. 

 loivensis, Asaphus, Calymene senaria, Ceraurus pleurexanthemus, Dalmania calli- 

 cephala, Spherocori/phe, sp.? andProetus? (fragment only). 



Tin's formation, without noteworthy modification, is again exposed by the Little Sua- 

 mico river, and outcrops along the shore of Green Bay, south of Pensaukee, and, al- 

 though largely concealed by drift, borders the bay northward into Michigan. 



Its last appearance in the state is at the lower rapids of the Menomonee river, a little 

 above Marinette, where a few feet are expised in the channel of the river. It is here 

 a bluish or greenish gray, impure dolomite of rather coarse, uneven, partly crystalline 

 and partly earthy texture, containing some cavities lined with calcite. Fossils are not 

 abundant. Dr. Rominger, in the Michigan report, cites the following: "Lingula 



