100 A. HYATT — GEOLOGY OF THE TAYLORVILLE REGION. 



and Arcestes, together with a Tropites which may be the young of the 

 species of this genus occurring in the Halobia slates. The forma com- 

 prise — 



1 | Arcestes-phylum of .1. tornati; Noric and Karnic. 



" A. galeaii : Noric. 



" A. bicarinati; upper Noric and lower Karnic. 



•• A. sublabiati : Karnic. 

 Badiotites, allied to B. eryx, Mojsis. ; upper Noric and lower Karnic. 

 Juvavites, allied to ./. erlichi, Mojsis. ; upper Noric and lower Karnic 

 Tropites, may he young of species occurring in Halobia slates; Karnic. 

 Atractites. 



Arcestes (1 ) is very abundant, but whether the other forms are abun- 

 dant or not it is difficult to say at present. The materials gathered show 

 that the rock is full of fossils, but these cannot be obtained in any reason- 

 able time by means of surface work. Besides the species mentioned, 

 there is a form of Acrochor dicer us, with finer costse than those occurring 

 in the Muschelkalk, a possible Balatonites, like B. waageni of the Noric. 

 and some other fragments of ceratitinse, all indicating a fauna rich in 

 ammonoids, which will some day yield a good harvest to patient work. 



General Remarks. — The results of explorations made up to the present 

 time admit of some general comparisons, which, although by no means 

 conclusive, are suggestive and interesting. 



The Trias of Idaho I Aspen mountains, near Soda springs) has a well 

 marked Triassic fauna, with fossil cephalopods recognized in Europe by 

 Mojsisovics, Steinmann and Karpinsky as belonging to the lower part of 

 the Triassic system, and. after careful re-examination of the fossils, I find 

 strong grounds for thinking that this opinion is probably correct, This 

 fauna appears to lie more nearly the equivalent of that of the Werferner 

 beds of the noddle Buntersandstein of the German Trias than of any 

 other. 



The Trias of the Star Peak range in the Humboldt region, Nevada, 

 contains an unmistakably younger fauna. Before reading the similar 

 opinion of Mojsisovics, published in Ins superb work "Die Cephalo- 

 poden der Mediterranean Trias-Provinz," I had arrived independently 

 at the same opinion, that this fauna belongs to the Muschelkalk and not 

 to the younger Saint Cassian stage, as formerly supposed. When the 

 species are properly published the parallelism with the Muschelkalk will 

 he readily -ecu. since well preserved cephalopods are abundant. 



Idle Trias of Taylorville is quite as interesting as that of the other two 

 localities, and it is very suggestive that its age, as indicated by the fossils. 

 is that of the Noric and Karnic series in the upper Trias. 



