330 



Report of the State Geologist. 



*Lunulicardium Livonise. rc 

 *Panenka retusa. rc 

 *Phthonia nodocostata. rc 



Amboccelia .umbonata. c 



Spirifer nmcronatus (small), c 



Liorhynchus multicostus. c 



Productella spinulicosta. c 



Orl)iculoidea media, c 



Stropheodonta perplana. r 



Those starred do not occur in the Eighteen-mile creek region, while some 

 of the others are especially abundant in the lower part of the lower shales at 

 Eighteen-mile creek. A comparison of the lists of species from the lower 

 shales of these two localities at once reveals the greater abundance in species 

 and individuals, of fossils at Eighteen-mile creek, indicating favorable condi- 

 tions which however ceased after the Encrinal limestone was deposited. The 

 complete extinction of many species before the beginning of the Spirifer 

 consobrinus fauna at Eighteen-mile creek, is remarkable, but what is equally 

 remarkable is that many of these species appear at Livonia in the Upper 

 shales where they make their first appearance in that region. Spirifer 

 granulosus, unknown in the Moscow shales of the Eighteen-mile creek, but 

 abundant in the lower and upper beds of the Lower shales and in the Encrinal 

 limestone of that region, makes its first appearance at Livonia, seventeen or 

 eighteen feet above the Encrinal limestone. The characteristic corals of the 

 Encrinal limestone and the coral layer " at Eighteen-mile creek appear five 

 feet above the former bed at Livonia, and above them Meristella Haskinsi 

 and Spirifer sculptilis occur abundantly. Pleurodictyum stylopora restricted 

 to the Pleurodictyum beds at the base of the Lower shales at Eighteen-mile 

 •creek, makes its first appearance sixty-five feet above the Encrinal limestone 

 at Livonia. 



The following sixty-eight species of fossils common in, and frequently 

 characteristic of, the Lower shales and the Encrinal limestone at Eighteen- 

 mile creek and vicinity, occur for the first time and usually in abundance, in 

 the Encrinal band and the Upper shales of the Livonia section. Those 

 starred pass upwards into the Upper (Moscow) shales at Eighteen-mile creek, 

 but with few exceptions are not very characteristic of them ; 



Crustacea : 



f*J Phacops rana. 

 +*2 Cryphauis Boothi. 



