30 PROCEEDINGS OF THE ACADEMY OF 1889.] 



sabre-tooth canine is of less breadth than in the former, and the 

 hiatus in advance is considerably less, indicating a proportionately 

 smaller inferior canine. The zygoma is absolutely deeper and flatter. 

 Of Machairodus neogaeus, we possess the cast of a skull, from the 

 bone-caverns of Brazil, the original of which is in the natural history 

 museum of Paris. Dr. H. Burmeister has described and figured a 

 complete skeleton of this species, from the pampas formation of the 

 Argentine Republic, preserved in the museum of Buenos Ayres. 

 Prof. Cope, in the "American Naturalist" of 1880, notices another 

 skeleton from the same region, under the name of Smilodon necator. 

 With Dr. Burmeister, Dr. Leidy regarded all these as pertaining 

 to one species, and thought it probable that the Florida skull 

 might also belong to the same. 



Comparative measurements of the Florida, skull, the cast of the 

 Brazil skull and Dr. Burmeister's figures of the Argentine skull are 

 given below, but some of them, from the imperfection of the means 

 are to be regarded as only approximative^ correct. The measure- 

 ments are given in millemetres. 



Florida. Argentine. Brazil. 

 Length of skull from occipital con- 

 dyles to incisive border . . . 285 330 330 

 Breadth of skull at widest part of 



zygoma 190 230 230? 



Depth of skull at post-glenoid tuber- 

 cle 125 164 160? 



Length of skull from behind zygoma 



to incisive alveoli 210 245 225 



Breadth at mastoid processes . . 126 143 140 



Breadth of narrowest portion of 



cranium 57 57 



Breadth at occipital condyles . . 105 112 



Breadth of face at sectorial molars 150 170 



Breadth of face at canines ... 94 112 110? 



Fore and aft space of the teeth . . 140 146 163 



Fore and aft space of two molars . 55 62 63 



Transverse space of the incisors . 58 66 55 



Breadth fore and aft of sectorial 



molar alveolus 37 43 42 



Breadth fore and aft of second pre- 

 molar alveolus 16 18 18 



Breadth fore and aft of canine 



alveolus 40 45 53 



Breadth transverse of canine alveolus 20 20 25 

 Breadth fore and aft of glenoid ar- 

 ticulation 25 25 



Breadth transverse of glenoid artic- 

 ulation 50 50 



Depth of face at infra-orbital mar- 

 gin 60 55 53 



Depth of zygoma 46 38 43 



