No. 2328. PLEISTOCENE VERTEBRATES IN UNITED STATES— HAY. 125 

 ALCES AMERICANUS Jardine. 



Plate 6, figs. 3-4. 



Of the existing moose there is found in the collection a single in- 

 cisor (Cat. No. 9118). It presents no differences when compared 

 with the same tooth of a recent specimen. It is shown here in com- 

 parison with the incisor of Cervalces rooseveltl (pi. 6, figs. 3, 4). 



Family BOVIDAE. 



SYMBOS PROMPTUS, new species. 



Plate 6, figs. 9-10; plate S, figs. 1-6. 



Type specimen. — An upper left third molar (Cat. No. 9120, 

 U.S.N.M.) 



Type locality. — Northeastern Oklahoma. 



Type formation. — Pleistocene. 



Diagnosis. — Upper molars with the external styles less strongly 

 developed than in S. cavifrons; the fossettes less angular. 



In the collection made near Afton are various remains of a musk 

 ox which appear to be referable to the genus Sy?nhos, but which do 

 not belong to any of the species described. There are present a 

 molar taken to be the upper hindermost (Cat. No. 9120), a part of 

 an atlas, a cervical vertebra, two dorsals, and one lumbar. All of the 

 vertebrae are more or less damaged by loss of parts. 



The upper molar (pi. 6, figs. 9, 10) is worn down to about one- 

 half of the original height of the crown. The present height is 

 about 25 mm. The length is 39 mm. at the grinding surface, on the 

 outer face of the tooth ; 38 mm. near the base ; and 36 mm. along the 

 middle of the width. The width at the base of the front lobe is 

 36 mm. On comparing this tooth with a photograph of the teeth of 

 a fine skull of Symhos cavifrons found near Ann Arbor, Michigan, 

 and described by Dr. E. C. Case,^ it appeared that the parastyle 

 and the mesostyle were less strongly developed than in S. cavifrons. 

 The tooth v/as, therefore, sent to Doctor Case for direct comparison. 

 He has kindly reported that the styles of S. cavifrons stand out 5 mm. 

 from the excavation forming the outer face of the front lobe ; while 

 in the Afton tooth this distance is only 3 mm. Also, the inner wall 

 of the fossettes of the molars of S. cavifrons is angular, while in 

 Si. promptus they are broadlv rounded. 



The writer has not seen the materials forming the type of Mr. 

 Barnum Brown's Symbos australis.^ However, the second molar, the 

 type of this species, is considerably smaller, the length at the base 

 being given as only 32 mm.; the width, 30 mm. The third molar 



1 Occ. Papers Mus. Zool. Univ. Mich., No. 13, 1915. 



» Mem. Amer. Mus. Nat. Hist, vol. 9, 1908, p. 203, pi. 22. 



