244 W. N. LOGAN 
longer applicable as they are unquestionably Jura. As the Red 
Beds represent the whole interva) of time from the Carbonif- 
erous to the Jurassic so far as evidence to the contrary is con- 
cerned the term Jura-Trias alone is not applicable to them. 
Continuing the section already begun we have for number 
11. Arenaceous clay of a somewhat shaly nature, 6’. This 
layer contains near the central horizon a more highly arenaceous 
stratum of greenish color. It has scattered through it at different 
levels some rather large brown argillaceous concretions. The 
entire stratum seems to be unfossiliferous but it may contain 
Belemnites densus as it is often difficult to determine whether this 
fossil does, or does not, belong to the lower beds, since, on 
account of its abundance in the upper beds, it is usually scat- 
tered superficially throughout the full extent of the outcrop. 
12. White sandy clay, 4’. No invertebrate fossils were 
found in this stratum but the remains of marine saurians belong- 
ing to the genera, /chthyosaurus and Plestosaurus occur in consid- 
erable abundance. 
13. Purplish fossiliferous clay containing calcareous nodules, 
20’. The most abundant fossil in this stratum is Belemnites 
densus which occurs distributed throughout the layer while the 
other fossils are confined chiefly to calcareous concretions. From 
these concretions the following forms were obtained: Pinna 
kingi Meek; Cardioceras? cordiforme M. & H.; Belemnites densus 
M.& H.; Astericus pentacrinus M. & H.; Astarte packardi White ; 
Pleuromya subcompressa \White; Pseudomonotis curta Hall; Lan- 
credia bulbosa White; Goniomya montanaensis Meek; Tancredia 
magna Logan; Lima lata Logan; Belemnites curta Logan; Car- 
dinia wyomingensis Logan and Avicula beedei Logan. This 
stratum contains also the remains of Plestosaurs and ILchthyosaurs. 
It is the most abundantly fossiliferous of the entire series. It is 
also one of the most persistent beds, and is everywhere charac- 
terized by the great abundance of Lelemnites. 
14. Greenish colored sandstone separating into thin layers, 
2’ to 4’. This stratum is very persistent, contains considerable 
calcareous matter, and is easily recognized on account of its 
