134 



University of California Publications. 



[Geology 



The species is named in honor of its discoverer, Mr. Frank C. 

 Calkins. 



But one other complete skull of Elotherium has been obtained 

 from the John Day. A number of years ago Messrs. Leander S. 

 Davis and William Day, while collecting for Professor Marsh, 

 discovered a perfect cranium in the lower Diceratherium beds in 

 the Blue Basin, Turtle Cove. This specimen, now in the Marsh 

 collection at Yale University, is a distinct species. 



Measurements. 



Total length of skull (316 mm 



Length of mandible 560 



Length P'-M 3 inclusive, on alveolar border 280 



Length W-W inclusive. 97 



Length M r M 3 inclusive 105 



Depth of mandible below P 2 78 



Depth of mandible below Mj 109 



P 3 , antero-posterior diameter 37.5 



P 4 , antero-posterior diameter 25.5 



M 1 , antero-posterior diameter 31.5 



M 1 , transverse diameter 33 



M 2 , antero posterior diameter 33 



M 2 , transverse diameter 33.5 



M 3 , antero-posterior diameter 31 



M 3 , transverse diameter 28 



M,, antero-posterior diameter 35 



Mo, transverse diameter 29 



M :! , antero-posterior diameter 34 



M 3 , transverse diameter 26 



Length of third metatarsal 168 



Length of astragalus 76 



Width across proximal end of astragalus 42 



thinohyus (bothrolabis) decedens Cope. 



PI. 16. 



Chaenoliyus decedens Cope. Pr. Am. Phil. Soc, Vol. XVIII, 

 p. 373, 1879, Vol. XXV, p. 63, 1888. 



Type. — Cranium in the Condon collection, Eugene, Oregon. Mandible, 

 No. 1989, Univ. of Cal. Palaeont. Coll. The mandible is associated 

 with part of a cranium in which I 3 , part of the canine, P 4 and Ms 1 ' 3 

 are preserved. 



Locality. — Diceratherium beds, Middle John Day. Near McAllister's 

 ranch, below Twickenham, Wheeler Co., Oregon. The specimen was 

 recovered from a horizon situated about fifty feet above the top of 

 the Lower John Day. 



