GALENA LIMESTONE. 



313 



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

 noteworthy of these is at Flintvllle, and as the section here best illustrates the pecuh- 

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



1. The lowest rook 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 orystalUne limestone, 

 mixed with earthy, argillaceous material, and at all points very fuU of OrtMs tefitiuVmaria. 



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

 ulitic forms of Chcetetes and Streptelasma corniculum. 



4. Above this, Kes a four-inch bed of deep blue, coarse-grained, crystaUine magnesian 

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

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

 ReceptaciiUtes Oweni, the characteristic fossO of the Galena limestone, while other fossils, 

 except minute crinoidal discs, are rare. 



6. 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, Orthis lynx, 0.pUcatella,Lei3tcena sericea, and other fossils. 



6. Next above, occm-s 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 httle else than a mass of the stems 

 of the branching Chcetetes. The numnhtic forms, as also Brachiopods and Tiilobites, 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 Recepiaculiies Oweni, 

 besides Orthis plicatella, 0. lynx, Lepfcena sericea, Strophomena alternata, Eaphistoma 

 lenticiilaris, and fragments of trilobites and crinoids. 



Tlie entire coUeotion made at this locaUty, which is given below, shows an interesting 

 mingUng of those species that are characteristic of the Galena hmestone in its typical 

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

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

 lasma corniculum^ two new species of Stictopora, lAngula attenuata ? Philodops truncafa, 

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

 naria, Memipronites Americanus, n. sp., Strophomena alternata, S. ihcvassata ? Lep- 

 tcena sericea, Zygospira recurmrostris, a new species of Ehynchonella, Pentamerus 

 (Camerella ?) hemipKcatus, Raphistoma lenticiilaris, Murchisonia hellicincta (slender 

 form), Murchisonia (slender form Uke M. gracilis, round volutions), Fiisispira elongata, 

 Bellerophon Uldbatus, Cyrtolites Dyeri, Endoceras proteiforme, Illcenus taurus, I. 

 lowensis, Asaphus, Calymene senarin, Ceraurus pleurexanthemus, Dalmania calli- 

 cephala, Spherocoryphe, sp. ? and Proetus? (fragment only). 



Tliis formation, without noteworthy modification, is again exposed by the Little Saa- 

 mico river, and outcrops along the shore of G.-een Bay, south of Pensaukee, and, al- 

 though largely concealed by drift, borders the bay noithward 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 exp-ised m the channel of the river. It is here 

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

 and partly earthy texture, containing some cavities Kned with calcite. Fossils a,re not 

 abundant. Dr. Eominger, in the Michigan report, cites the foUowing: "Lingula 



