GENERAL REMARKS. 203 



On that account, it will prove to be of very great interest in a stratigrapliical 

 point of view. 



The section of the formations in the Western Oquirrh Mountains, in 

 which Dry Canon and Snowstorm Hill are situated, is likely to prove one 

 of the most instructive of the Western Palaeozoic localities, as in it will 

 probably be found the most complete representation of the Palaeozoic for- 

 mations, extending from the quartzites of Ophir City (which are likely to 

 prove as old as Huronian, being overlaid by shales bearing Trilobites of 

 Primordial age) to these Weber quartzites, lying above the beds contain- 

 ing the Lower Carboniferous fossils. The layers of limestones between the 

 Trilobitic shales and the limestones furnishing Waverly group fossils, two 

 thousand feet in thickness, undoubtedly represent the Silurian and Devonian 

 formations, and will probably, when thoroughly examined, yield fossils of 

 these formations in some of their outcrops. 



The rocks at this locality are said to change gradually, in passing 

 upward, from a limestone to a quartzite, and above, having limestone bands 

 interstratified. If such be the case, some of these limestones will most prob- 

 ably yield fossils on thorough examination, and show a gradual change 

 from a Lower Carboniferous to a Coal-Measure fauna. 



A few additional species furnished by the later collections from the 

 Upper Coal or Permo-Carboniferous beds of the Weber River section, wdll 

 be found figured on plate VL 



On plates VI and VII are given a few forms each of Triassic and Juras- 

 sic species. The later collections from these fomiations are rather unsatis- 

 factory in their character, and not very abundant. There is one group, how- 

 ever, of special interest, labeled as coming from Shoshone Springs, Augusta 

 Mountains. Of the age of these beds we are not at all satisfied. Mr. King 

 and his associates are inclined to place them as low as Jurassic or even Tri- 

 assic. Tliis view may be correct. The species are all of undescribed forms, 

 and therefore of but little stratigrapliical value. The generic value of the 

 Aviculopeden-Wke shell would indicate an age at least as great as this, if the 

 generic reference is correct, about which there may possibly be some doubt ; 

 but the features of some others would incline one to believe them of much 

 more recent date, especially the two described under the new generic name 



