196 



Report of the State Geologist. 



XXIV C 5 . Along the outlet of Arnold lake, about 135 feet lower than 

 the top of Bowie hill, are quite fossiliferous bluish sandstones and shales. 

 Lower, along the highway to the southwest, are bluish thin shales with layers 

 of thin concretionary sandstones which contain specimens of IAorhyncfws 

 mesacostalis, Hall, and Spirifer mucronatus (Con.), Bill. This fauna resembles 

 very closely the first of the Ithaca fauna as it appears at the top of the Sher- 

 burne formation, to which horizon these rocks are referred. The following 

 species were obtained from the bluish shaly sandstones at the outlet of the 



lake and have been referred to the Ithaca fauna: 



1. LiorhyncJms mesacostalis, Hall. (c) 



2. Spirifer mucronatus, (Con.), Bill. (c) 



3. Spirifer mesastrialis. Hall. (c) 



4. Grammysia elliptica, Hall. (it) 



5. (?) Terebratula (Mtinella) LincMaevi, Hall. (c) 



The imperfect form in which these specimens are preserved 

 renders their identification difficult. Possibly they are narrow 

 specimens of (Jryptonella Eiidora, Hall. 

 Arnold lake is well surrounded by hills with steep banks, and the ice of 

 the glacial period probably excavated its basin. 



C e . On the divide to the east of Arnold lake, from C 5 and somewhat 

 higher, are thin olive shales and sandstones in which no fossils were found, 

 except fucoid markings. The lithologic characters of the rocks and the ab- 

 sence of fossils make this outcrop agree closely with those in the Sherburne 

 formation. To the east is a very steep hill, dropping 300 feet into the valley 

 of Hinman Hollow brook; but, unfortunately, its tlank is mostly covered 

 by drift. 



XXV A 1 . On the small divide between Hinman Hollow brook and a 

 small branch from the western side not over a mile to the northeast of Arnold 

 lake, and 290 feet below the divide at C 6 , are ledges of coarse, bluish, arena- 

 ceous shales containing Hamilton fossils in abundance. The outcrop is on the 

 north side of the road and is an excellent locality for collecting. There can 

 lie no doubt in reference to the Hamilton age of these rocks. The fauna is: 



1. Ally ii.< spi/riferoides (Eaton), Hall. (a) 



2. Cyrtina Hamiltonensis, Hall. (c) 



3. Spirifer <j ran uloxux (Con.), Hall. (c) 



4. Spirifer m iicroiuil us (('on.). Bill. (c) 



5. Spirifer fimbriatus (Con.), Hill. (c) 



6. Clionctis srif ///(/, Hall. (a) 



