258 VERTEBRATE REMAINS, PORT KENNEDY BONE DEPOSIT. 



plication of the enamel and the dimensions, agree with the superior molars typical 

 of E. fraternus. The symphyseal region is rounded and not keeled below, and the 

 incisors, as above described, have the deficient interior plate, except the I T , where 

 it is present, differing in this respect from the Florida individuals. The mental 

 foramen issues opposite the posterior border of the symphysis. 



Measurements. 



mm. 

 Length of inferior molar series ; 190 



tv \ anteroposterior ; 33 



Diameters, pm T { , l -, n 



' L 3 ( transverse ; lb 



tv ( anteroposterior; 30 



Diameters, pm. T -, , r -i a 



1 - ( transverse ; lb 



tv (anteroposterior; 27 



Diameters, in T { , 1f 



1 ( transverse ; 1 b 



tv T { anteroposterior; 10 



Diameters, 1 T < , l -,r 



' i ( transverse ; lo 



tv T | anteroposterior ; 7 



Diameters, l-o < , l -, n 



' ° | transverse ; 1 b 



Depth of ramus at anterior border pm-g- ; 80 



Distance from I ¥ to canine ; 12 



The fragment of a second lower jaw resembles closely the one just described. 

 Some other bones of the skeleton have the following : 



Measurements. 



mm. 



Least anteroposterior diameter of scapula; bo. 5 



Anteroposterior diameter of scapula at coracoid ; 104 



tv , j? i -j -j. c n I anteroposterior; b4 



Diameters <>i ulenoid cavitv ot scapula < , L ro 



J L \ transverse ; 53 



Length of bone at middle of side ; 83 



Distal transverse diameter at middle ; 44 



Length of coronary bone at middle of side ; 39 



" of coffin bone ; 58.5 



Greatest width of bone ; 89 



tv . l t r- , i o ( anteroi)osterior ; 35 



Diameters, proximal end ot metacarpal o < , L cr 



1 L \ transverse ; 55 



The deficiency of the posterior wall of the incisors is the dental character 

 which distinguishes this species best from E. cabal/us. The enamel plications of the 

 superior molars are also a little more complex than is usual in the common horse. 

 What other characters distinguish Equus fraternus can only be determined by 

 the accession of new material from other parts of the skeleton. 



The preceding observations show that two varieties of one -species, or two 

 distinct species of horse as large as the domestic animal, were a notable feature of 

 the fauna whose remains were entombed at Port Kennedy. 



