THE CINCINNATI SHALES AND LIMESTONES. 3] 7 



175 feet below the base of the Niagara limestone, on the east side of Lake Winnebago, 

 and is found at other points, constituting a portion of the series. 



In the adjoining section (Sec. 10, N. W. qr.), the Niagara limestone, which consti- 

 tutes Hinkley's quarry, rests upon a dark blue, hard clay, constituting the upper mem- 

 ber of the formation. The transition is abrupt, as is befitting the junction of the Lower 

 and Upper Silurian formations. 



North of this, the formation is concealed by drift, and, except as occasionally struck 

 by a well, is not again accessible to observation until Roberts' quarry, on the south side 

 of Pewaukee Lake, is reached. This quarry, like the last, is in the lower beds of the 

 Niagara limestone, and has for its floor the clay.like shale of the formation under con- 

 sideration. Fortunately for the geologist, however unprofitable for the owner, some 

 " experienced miner," in his " practical " wisdom, had discerned in this the Coal forma- 

 tion (!), and expressed the belief that coal would be found beneath the shale; so a shaft, 

 was sunk, from which was thrown a remarkable abundance of beautifully preserved Low- 

 er Silurian fossils, but, it is needless to say, no "fossil fuel." The shaft and boring to- 

 gether reached a depth of 50 feet, and showed an alternating succession of blue shale, 

 and gray, yellow, and blue limestone, associated with some crystalized quartz, and with 

 considerable iron pyrites. Among the fossils collected from the material thrown out of 

 this shaft, there were found no less than sixteen species of Chaetetes, nine of which are 

 regarded as new. With these are associated two species of Stellipora, one of Dc- 

 kayi, two of Stictopora, several new species of Trematopora, a Fenestella, a Retepora, 

 an Alecto, and two of Callopora, making nearly thirty species of Bryozoans and Corals. 

 Of other forms, there were found five species of Orthis, six of Strophomena, Crania seti- 

 gera, Zygospira modesta, Pterinea demissa, Calymene senaria, an Illcenus, a new spe- 

 cies of Beyrichia and one of Ortonia. These all came from the upper 10 feet of the shaft. 

 Passing onward, the formation is again effectually concealed, till the town of Aship- 

 pun is reached. In Sec. 6 of this town, and Sec. 1 of the adjoining town of Lebanon, 

 small streams have denuded arenaceous beds identical with the rock described as occur- 

 ring in the drift in the town of Eagle. At other points in this vicinity the presence of 

 the formation is sufficiently indicated, even though it does not display itself in actual 

 outcrops. 



At Hartford, these shales underlie the iron ore bed, and are penetrated by cellars, 

 wells, and other excavations. 



The portion here exposed is the upper stratum, and has its usual characteristics, being 1 

 a blue, clay-like, fossiliferous shale, containing some limestone. 



The following list of fossils will be of local interest: Several species of Chcetetes, 

 among which are C. annuliferus, C. rhombicus, and a new species, Stictopora fragilis, 

 Orthis testudinaria, 0. subquadrata, 0. occidentalis, Leptcena sericea, Strophomena uni- 

 costata, Rhynchonella capax, and some undetermined forms. With more favorable 

 exposures, this locality would doubtless prove prolific in interesting species. It may be 

 remarked as a practical suggestion, that the iron ore beds, when present, always lie 

 above this formation, except where disturbed by the drift. 



Beneath the mines at Iron Ridge, and in the vicinity of the upper portion of the 

 formation, is a light greenish blue, scarcely indurated clay, not very fossiliferous. Be- 

 low this the shale is darker and more full of fossils. As usual, interstratified beds of 

 limestone are present. The upper surface of the clay mingles with the iron ore above 

 for one or two feet, rendering it too impure for use. 



The following interesting collection was made at this point : Chcetetes rhombicus, n. 

 sn., C. briareus, C. punctatus, n. sp., and several other new or undetermined species, 

 Alveolites, n. sp., Aulopora arachnoidea, Alecto inflata, Stellipora antheloidea, Sticto- 

 pora fragilis, a Helopora, a Lingula, Orthis testudinaria, 0. lynx, 0. subquadrata, 

 and an undetrmined species, Strophomena unicostata, an undetermined Strepto- 



