184 ruocJcicDiXGS of the acadkmy of [1890. 



Mastodon and Capybara of South Carolina. — Professor Leidy 

 directed attention to several f(j.ssil.s and made the following remarks. 

 The exploration of the ])hosi)]iate beds of the South Atlantic States 

 })romises to give usjnuch information of the qnatenary fauna of the 

 region. jNIany interesting forms, both terrestrial and marine, have 

 been brought to our notice. Recently, the fine specimen of a 

 Mastodon tooth exhibited, looking as if carved out of ebony, as is 

 the case with many of the fossils from the same and similar localities, 

 \yas presented to the Academy by Mr. James R. McKee. It was 

 found in the Santee Beds of Beaufort Co., S. C. It is the complete 

 crown of a last upper molar, strikingly different from that tooth in 

 the common x\merican Mastodon. It is worn only on the summits 

 of the anterior pair of lobes, which display the usual exposed 

 dentinal areas. Notwithstanding the many species of Mastodon 

 which have been recorded in North and South America, the present 

 tooth seems to indicate a different one. It more nearly resembles the 

 corresponding tooth of the M. florldanus, recently described, or that 

 of the M. angustldens of Europe, than of the M. americanus. In 

 comparison with the molars of these and other known species the 

 tooth is remai'kable for the greater proportionate length of the con- 

 stituent lobes of the crown and their conspicuously wrinkled condi- 

 tion. The wrinkling is longitudinal and regular and apparently not 

 the result of an abnormal state. Similar wrinkling is observed 

 in some specimens of the same teeth in M. americanus, but mainly 

 confined to the intermediate vallies of the crown, while it is well 

 produced laterally in the present fossil. From the comparatively 

 more prolonged condition of the lobes, the summits of the inner ones 

 appear more tapering or narrowly pointed than in 31. fioridanus ; 

 while with the fore and aft extensions of the same lobes the summits 

 form acute and not obtuse angles as in the latter. Regarding the 

 specimen as indicating a previously unknown species, this may be 

 distinguished as the Mastodon rugosidens. 



Comparative measurements of the tooth are as follows : 



M. rugosidens. M. flo]'idanus. 



Length of crown fore and aft 



Breadth of base at fore part 



Length of second inner lobe 



Length of second outer lobe 



The second fossil is a fragment of an ui)per incisor of a Capybara, 

 from Ashley River, South Carolina, submitted for examination by 

 Mr. Edwin E. Howell, of the firm of Ward and Howell. Some speci- 

 mens of molar teeth from the same locality, previously described, do 

 not differ in any respect from those of the living species, but from 

 the conditions under which tliey Avere found were referred to a differ- 

 ent one with the name of Hydrocho'rus cesopi (Proc. 1856, 165). 



The present fossil accords in anatomical character except size 

 with the corresponding part in the living Capybara. Its compar- 

 ative measurements areas follows: 



