MARINE SEDIMENTS OF EASTERN OREGON 225 



limestone has been ascertained and more fossils collected from 

 it. Mr. Nelson writes that he found the fossils in situ in limestone 

 east of Big creek, about three miles south of Medical Springs. 

 He says that the limestone extends in a broken line through Tp. 

 7 S., R's. 41, 42, and that it contains fossils in many places. 

 Lindgren's map shows only Triassic in this vicinity. The fossils 

 were referred to Dr. George H. Girty, to whose kindness the 

 writer is indebted for the following report: 



The unfortunate preservation of the material from Oregon is such as to 

 render a nice discrimination of species impossible. Among the Prodiicti 

 there appear to be at least three species, one of these a large, comparatively 

 flat, and spreading shell, which cannot be identified. Another group con- 

 sists of small shells, which can be almost exactly duplicated in Marginifera 

 sple7tdens N & P of the Mississippi valley, a species frequently cited as Pro- 

 ductus longispmus, I have not, however, been able to make out the internal 

 characters distinguishing the genus Marginifera. The third group comprises 

 forms more or less closely related to Productiis miiltistriattis Meek. All of 

 these specimens are smaller than typical P. inultistriatus , and some are more 

 coarsely striated. These shells vary so much in these two characters, size, 

 and striation, that I suspect that more than one species is represented. The 

 material, however, will not permit this fact to be satisfactorily determined. 

 Besides the forms mentioned are a ^Spirifer or Spiriferina (probably the 

 latter), a Setninula not unlike some forms of S. subtilita from the Mississippi 

 valley. 



The only other place in eastern Oregon in which Paleozoic 

 fossils have been found is on upper Crooked river. The fos- 

 sils occur in partly crystalline limestone on upper Beaver creek, 

 near the crossing of the Prineville-Izee wagon road. They were 

 discovered by Mr. John Platts and the writer while on a bicycle 

 trip in 1899. 



Dr. Girty reports on them as follows : 



The following species have been identified : 



Zaphrentis sp. 



Brachiopod ? 



Avictilopecten sp. 



Pseudomonotis sp. 



The shell referred to as Brachiopod is indeterminable. 



The third-mentioned form is probably an Aviciilopecten, but it belongs to 

 no species with which I am familiar, and certainly not to the common Car- 

 boniferous ones. 



