56 Gooch and Kobayashi — Platinized Anode of Glass. 



These results show plainly that the estimation of manganese 

 by electro-deposition of the hydrated dioxide upon the rotating 

 anode of platinized glass, and subsequent conversion of the 

 manganese to the anhydrous sulphate, is entirely feasible. 

 From the electrolyte containing in a volume of lOO'^™^ approxi- 

 mately 0*1 grm. of manganese in the form of sulphate, acetic 

 acid (S'^"^'), and chrome alum (0*5 grm.) the time required for 

 the complete deposition of the hydrated manganese dioxide 

 was two and a half hours ; and when alcohol (5"^"^"), preferably 

 with ammonium sulphate (2 grm.), was substituted for the 

 chrome alum (0*5 grm.) the time required was extended to a 

 safe minimum of three and a half to four hours. 



Art. Y. — Preliminary Note on the OccurrenGe of Yerte- 

 l)rate Footprints in the Pennsylvanian of OTdahoma ; by 

 WiLLARD Rouse Jillson. 



During the summer of 1916, while mapping the structural 

 geology of a portion of the Osage [N'ation. Oklahoma, the 

 writer had the good fortune to discover a series of casts of ver- 

 tebrate footprints in one of the sandstone members of the 

 Middle or Lower Pennsylvanian. The location of the bed con- 

 taining these fossil trails is in Township 27 North, Range 10 

 East, Section 31 in Elm Creek about six miles northeast of 

 Pawhuska. Stratigraphically the clay-sandstone member in 

 which the casts of the animal tracks are preserved is calculated 

 to be about 200 feet below the top of the Elgin sandstone 

 which Adams, Girty, and White"^ regard as the Oklahoma 

 equivalent of the Kanwaka shales of Kansas. As the Elgin 

 sandstone is somewhat thicker in Oklahoma than in Kansas 

 this would correlate the track-bearing horizon of the formation 

 with the uppermost part of the Le Roy shales of Kansas. f 

 This correlation fixes these beds as middle or lower Pennsyl- 

 vanian, which is probably as close a determination as can be 

 made until the Oklahoma Carboniferous and Permian in their 

 relation to the Kansas equivalents are better understood. 



Fossil footprints, or casts, from this undoubted marine hori- 

 zon of the Oklahoma-Pennsylvanian series have never before 

 been described, and because of their rarity such occurrences 

 are to be regarded with interest. The slab on which the casts 



* Upper Carboniferous Eocks of the Kansas Section, U. S. Geol. Surv. 

 Bull. No. 211, p. 45, 1903. 

 t Idem, pp. 65-66. 



