DEVONIAN FAUNA. 75 



Atrypa desquamata. Paracyclas occidentalis. 



Atrypa reticularis. Microdon macrostriata. 



Meristella nasuta. Anadontopsis amygdalffifonnis. 



Ehynchouella tethys. Sckizodus orbicularis. 



Cryptonella circula. Platyceras nodosum. 



Pentamerus comis. Loxonema nobile. 



Pterinea flabella. Bellerophon pelops. 



Mytilarca dubia. Tentaeulites gracilistriatus. 



Plethomytillis oviforme. Orthoceras (2 sp.t). 



Modiomorpha altiforme. Beyrichia occidentalis. 



Modiomorpha obtusa. Phacops rana. 



Goniophora perangulata. Dalmanites rneeki. 



Megainbonia occidualis. Proetus marginalia. 

 Edmondia pifionensis. 



About 500 feet above this belt, in the dark gray limestone, occurs a 

 group of fossils, mainly silicified corals, as follows: 



Paleomanott roemeri. Cyathophyllum davidsoni. 



Stroinatopora. Cyathopliyllum rugosuin. 



Favosites basaltica. Diphyphyllum simcoense. 



Favosites hemispherica. Cystiphyllum americanum. 



Favosites, n. sp. Zaphrentis, sp. !. 



Syringopora perelegans. Atrypa reticularis. 



Above this latter grouping only a few fossils were found, mainly species 

 like Atrypa reticularis and Styliola fissurella, which occur all through the 

 epoch. In this long list of species from the base of the Devonian at Lone 

 Mountain, only seven forms occur which are known in the Upper Devonian, 

 the list as a group being decidedly Lower Devonian in character. Skenidiwn 

 devonicum is the only species of this genera which is known above the 

 Silurian, while Atrypa desquamata, here associated with A. reticularis, occurs 

 only in the lower beds. The Devonian trilobites in this list occur in 

 nearly all the other fossil-bearing beds at the base of the Nevada limestone 

 namely, Combs Peak, Atrypa Peak, Brush Peak but are not found in the 

 middle or upper horizons. It will be noticed that the list includes quite a 

 number of species usually regarded as characteristic types of the Upper 

 Helderberg. 



At Combs Mountain, Atrypa Peak, Brush Peak, Modoc Peak, and 

 several other localities occur fossiliferous calcareous shale bands well defined 



