DEVOIHAN FAUNA. 



75 



Atrypa dosqnainata. 

 Atr>^1a rctirulaiis. 

 Meristella iiasuta. 

 Eliyiicliouella ti^thys. 

 Cryptouella circula. 

 Peutamerus comis. 

 Pteriuea flabella. 

 Mytilarca dubia. 

 Pletbomytillis oviforme. 

 Modioniorpba altitbrme. 

 Modiomorpba obtusa. 

 Gouiopbora i)eraiiguhita. 

 Megaiubouia occidualis. 



Paracyclas occidentalis. 

 Microdon macrostiiata. 

 Aiiadontopsis amygdalffiformis. 

 Schizodu s orbicu 1 a ris. 

 Platyceras nodosum. 

 Loxonema iiobile. 

 Bellerophon pelops. 

 Teiitaculitcs gracilistriatus. 

 Orthoceras (2 sp.?). 

 Beyricbia occidentalis. 

 Pbacops rana. 

 Dalmanites nieeki. 

 Prcetus marginabs. 



Edmondia pifioneusis. 



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

 group of fossils, maiuly silicified corals, as follows: 



Paleonianon rocmeri. Cyatbopbylbim davidsoni. 



Stromatopora. Cyatboi)bylhim rngosnin. 



Favosites basaltica. Dipbjqibylbun simcoense. 



Favosites beniispberica. Cystipbyllum anieiicaniim. 



Favosites, u. sp. Zapbrentis, sp. ?. 



Syriugopora perelegans. Atrypa reticuhiris. 



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

 like Atrypa reticuhiris and Styliola Jissurella, which occiu- all through the 

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

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

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

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

 Silurian, w\a\Q Atrypa rfesg'Mawmf a, 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 usuall}- 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 



