302 GEOLOGY OF EASTERN WISCONSIN. 



low. By following up the stream, a strong dip to the north of east may be observed. 

 Fossils are not abundant here, and but few species were collected, although the quarry- 

 ing and natural exposures afforded ample opportunities. A few rods west of the busi- 

 ness center of the city, the lowest layers of the formation are about 40 feet higher than 

 at the falls. Along the bluff, in the western part of the city, the same layers are 25 to 

 30 feet higher still, from which point they dip to the south until they disappear beneath 

 Crystal creek at a lower point than that at which they occur to the east in the southern 

 part of the city. To the west of this, toward Green Lake, the base of the formation is 

 more nearly horizontal. In section 5 of the township of Ripon, about three miles north- 

 west of the city, the junction in question occurs at a lower elevation, if an aneroid meas- 

 urement is to be trusted, than at any of the preceding points. 



All these variations may be readily accounted for by supposing a changeable dip of 

 a few degrees; but they are nevertheless unusual in this formation. As the floor of the 

 formation has its greatest elevation at and in the vicinity of the point where it rests 

 upon the domes of Lower Magnesian limestone previously described, and has a lower 

 elevation as it recedes from this point, it is reasonable to suppose that the phenomena 

 may be due to that relationship. 



The following species representing the fauna of the lower beds of the formation were 

 collected in this vicinity, the quarries of Mr. Coombs and Mr. Corlis proving most pro- 

 lific : Buthotrephis succulens, B. gracilis, Chcetetes, Streptelasma corniculurn, Retepwa, 

 Trematopora, n. sp., Lingula, like L. obtusa, Stictopora, Orthis perveta, 0. tricenaria, 0. 

 subquadrata, Streptorhynchus deflectum, S. deltoideum, S. filitextutn, S. planumbonum, 

 Strophomena alternata, S. camura, S. incrassata, S. tenuistriata, Rhynchonella, n. sp., 

 Tellinomya nasuta, Cypricardites rotundatus, C. subtruncatus, C. ventricosus, C., n. sp., 

 Modiolopsis superba, Helicotoma planulata, Raphistoma lenticularis, Trochonema am- 

 bigmim, T. umbilicatum, Pleurotomaria subconica, Murchisonia bicincta, Holopea, Siib- 

 iiMes elongatus; Orthoceras annellum, 0. junceum, 0. vertebrale, 0. planoconwxum, 

 0., sp. new, Cyrtoceras (Oncoceras) plebeium? C. Pandion, C. or Gyroceras (outer cham- 

 ber only), Ormoceras, Gyroceras convolvans, Lituites, Illoenus taurus, Encrinurus, Lep- 

 erditia fabu lites, Ceraurus pleurexanthemus. 



North of Ripon, the formation soon becomes doubly covered with drift, being over- 

 laid not only by the original glacial deposit of rubbish, but also by the later lacustrine 

 clays, and hence it presents itself at the surface even more rarely than before, so that 

 our attention is not again demanded by the meager and scattered exposures until we 

 reach the vicinity of Neenah and Menasha, where a cluster of interesting quarries 

 occur. Leaving out of consideration those directly south of Neenah and north of Me- 

 nasha, which are referred to a higher horizon, we find a belt of quarries beginning with 

 Thompson's in Sec. 29, Neenah, and extending north to the county line, which possesses 

 the general lithological characters of the Upper Buff beds, which have already been ful- 

 ly described. The following list of species, however, collected from this belt, shows 

 several forms not observed in that horizon in the southern part of the state, but which 

 are common in a higher position and which therefore give special interest to the fauna 

 of these localities: Two new species of Chcetetes, Streptelasma corniculum, Columnaria, 

 a new species of Stictopora, Schizorinus nodosus, Lingula quadrata? Orthis lynx, 0. 

 plicatella, 0. subquadrata, 0. testudinaria, 0. pectinella, Streptorhynchus deflectum, S. 

 filitextum, Strophomena alternata, S. incrassata, S. camerata, Leptoena sericea, Zi/go- 

 spira recurvirostris, Rhynchonella Anticostensis, Raphistoma lenticularis, Pleuroto- 

 maria subconica, a new species of Murchisonia, having a lofty spire, Endoceras pro- 

 teiforme, an undetermined Gyroceras and Leperdita alia? were secured in the limited 

 time that could be devoted to collection. 



In the vicinity of Mr. Verbeck's residence, near the southeast corner of section 18, 

 Menasha, are several small quarries that possess interest from their position and char- 



