MESOZOIC OF SOUTHWESTERN OREGON 549 



cannot be accepted as throwing much light on the definite age of the 

 Franciscan. The forms were rather imperfect. The Hoplites was 

 said to be identical with or near to H. dilleri which has been found in 

 the Knoxville. Whether the Franciscan includes representatives of 

 the Lower Cretaceous, Jurassic, or (and) intermediate time, there 

 is no reason why some forms should not range from the Franciscan 

 into the Knoxville with the same, or with but slightly different, 

 characters. Indeed, considering that the Mariposa beds of the 

 Sierra Nevada, now for some time accepted as Jurassic, were believed 

 by White, 1 in the eighties, to be contemporaneous with the Knoxville 

 on paleontological evidence, and both were referred to the Lower 

 Cretaceous by Becker, 2 we have good reason to expect that some 

 faunal similarities would exist. 



In connection with the Opis calijornica found in the Whitsett 

 limestone, it may be pointed out that an imperfect fossil from the 

 base of the Franciscan on the northeast slope of Montana Mountain — 

 part of the Franciscan type area — was also referred by Stanton to 

 the genus Opis. 3 



In general, it may be added that, as several geologists have at 

 times confused the Knoxville and the Franciscan in various localities, 

 considering the latter a metamorphosed facies of the former, it is 

 possible that certain "Knoxville" localities credited to some of the 

 fossils are, in reality, Franciscan. 



The Jurassic question. — At several localities in the region under 

 discussion fossils have been found which have been referred to the 

 Jurassic. At Bucks Peak, some miles southwest of the Roseburg 

 quadrangle, a sandstone carries fossil leaves which have been referred 

 to the Jurassic by Professor Fontaine; and, in the bed of Elk River 

 in the Port Orford quadrangle, loose pieces of shale were found 

 containing plants which he considers of the same age— Lower Oolite. 

 The shales were not recognized in place. On Johnson Creek Diller 

 found fragments of shale containing Aucella, which Stanton refers to 

 the Upper Jurassic — Mariposa beds. According to Diller, "the 

 Jurassic sediments closely resemble those of the Myrtle formation, 



1 U. S. Geological Survey, Bulletin 15 (1885), pp. 24-26. 



2 U. S. Geological Survey, Bulletin ig (1885), pp. 18-20; also Bulletin of the 

 Geological Society of America, Vol. II (1891), p. 206. 



3 U. S. Geological Survey, Fifteenth Annual Report (1895), p. 443. 



