CARBONIFEROUS 333 



No. 30F : 



Orthis ? sp. Leiorhynchus ? aff. mesicostale Hall. 



Chonetes aff. ilUnoisensis Worthen. Rlujnclwnella ? aff. eurekensis Wal- 



Productiis ? (possibly aff. P. hirsuti- cott. 



formis Walcott). Ostracoda undet. 



Station opposite Mouth of Goleen River 

 No. 33 : 

 Fucoidal markings. Euomphalus aff. suhquadratus Meek 



and Woi-tbeu. ? " 



The fossils from lots 28 to 28B are from the Indian village section 

 shown on a preceding page. 



The suggestion of the presence of representatives of the early Missis- 

 sippian fauna which Girty finds in the invertebrate fauna listed above is 

 supported by the evidence of the fossil plants which were obtained a few 

 miles below the stations represented by the preceding fauna, at the first 

 rock outcrops encountered in ascending the river. Dr David White's 

 report on these plants is introduced here as bearing on the age of tlie 

 Carboniferous rocks below the Lower Eamparts of the Porcupine: 



"The collection transmitted by Doctor Kindle contains several small frag- 

 ments of a fern, 8phenopteris frigida Hr. ; several pieces of a large fern racbis 

 of unknown generic identity ; small rootlets probably belonging to Stigmaria; 

 and a single very fragmentary and obscure example of Lcpidostrohus. 



"Tbe material is insufficient for the satisfactory determination of the age of 

 the beds, but if the identification of the Sphenopteris is correct, the species 

 points strongly to a position in the lower part of the Lower Carboniferous, and 

 probably the basal member of the Mississippian. On account of the distribu- 

 tion of this fern in the Arctic region near the base of the Mississippian, it 

 seems probable that the discovery of additional fossils will prove the beds to 

 belong to that horizon." 



The lithologic characteristics of the beds yielding the plant fossils is 

 shown in the following section, number 27 : 



Section at first Outcrops on the Porcupine above Fort Yukon 



Feet Inches 

 i. Quartzite and sandstone, with some interbedded gray shales. . . 40 



h. Hard, bluish gray, siliceous shale 10 



g. Gray quartzite 30 



f. Black graphitic shale 3 



e. Buff to creamy white fireclay . . 20 



d. Sandstone • • 5 



c. Buff, fine-grained fireclay 1 



h. Black, soft graphitic shale G 



a. Thin-bedded gray quartzite, weathering brown (base) 15 



