SUBORDER C 



PEOBOSCIDEA 



261 



rugosidens Leidy, are less known. M. humbolcUi Cuvier occurs in Central 

 and South America, being very abundant in the later Pampas formation, 

 Avhile M. andnini GwYiQV is found in western South America.^ Entire skeletons 

 of M. americanus are not especially rare in North America.^ The synonymous 

 term of Mammut Blumenbach is employed by some writers in preference to 

 that of Mastodon. 



Stegodon Falconer (Figs. 346, 347). A form transitional between Mastodon 

 and Elephas connected by M. latidens with Mastodon. Lower incisors absent, 

 upper incisors powerfully developed, without a band of enamel. Molars 

 composed of from six to twelve low, roof-shaped, slightly convex, and usually 

 multipapillose transverse crests, the intermediate valleys being partially filled 

 with cement. In a given jaw, the first and second molars as a rule have an 

 equal number of crests ; the teeth of the mandible usually exhibit more 



Fig. 349. 



Eleplias primigenius Blum. Pleistocene, Essex. Upper molar, lateral aspect (A), and grinding surface (B). 1/5. 

 c, Cement ; d, dentine ; e, enamel. (After Owen.) 



ridges than the corresponding upper molars. Middle and Upper Pliocene of 

 southern and eastern Asia. Stegodon insignis Falc. and Caut., >S^. bombifrons 

 Falc. and Caut,, and S. ganesa Falc. and Caut. Pleistocene of the Narbada 

 Valley and S. airawana Martin from Java. 



JEhphas Linn. (Figs. 348-350). Dental formula : ^'^'^'^' (more rarely 



1.0.2.3. 



)• Upper incisors without band of enamel. 



0.0.0.3. 



.^^^^ „. Molars consisting of 



0.0.2.3. 



from five to twenty-seven deep, compressed transverse plates, with indented 

 superior margin, the intermediate valleys being completely filled with cement, 

 which also covers the entire crown of the tooth. A plane surface is produced 

 through wear. Three milk cheek teeth precede the molars and have some- 

 what less numerous transverse ridges. In the Indian elephant, the first 

 milk molar is shed in the second year, the second in the fifth year, and the 



^ JVordenskjold, E., Mastodon andium. K. Svensk. Vet.-Akad. Handl. , vol. 37, No. 4, 1903. 



- Clarke, J. M., Mastodons of New York. New York State Mus. Bull., No. 69, 1902.-- 



Oshorii, H. F., Mastodons of the Hudson Highlands. Natural History (New York), vol. xxiii., 1923. 



