ANCHITIIERIUM. 71 



side of the outer lobes ; in this course becoming dilated into a small conoidal pro- 

 cess about the middle. 



These teeth are not bounded by a basal ridge internally, but portions exist ante- 

 riorly and posteriorly ; and in the latter position inclose a small conoidal process. 



The first upper molar of the normal series is much smaller than the others, as is 

 indicated in the specimens by two small fangs, one before the other. 



The inferior molars (X. 14-17; XI. 5-8,) also are exceedingly like those of 

 ■Palaeotherium. Their crowns are composed of two lobes placed one before the 

 other, except the last of the series, which has an additional, or third lobe. The 

 lobes are demiconoidal, with their outer side angularly convex and their inner side 

 concave and sloping. Their summit is V shaped ; and the posterior extremity of 

 this rises to the apex of a pyramidal process of the inner side of the crown. The 

 anterior extremity of the summit of the anterior lobes curves to the base of the 

 anterior pyramidal process, while that of the summit of the posterior lobe ceases 

 upon the outer side of the same process. In the unworn teeth the apex of the 

 anterior pyramidal process is indented. The third lobe of the last molar is smaller 

 than those in advance, is ovoidal in form, and has a crescentic summit inclosing a 

 concave fossa. 



The inferior molars have no continuous basal ridge, but a portion exists between 

 the bases of the lobes externally, in the form of a small pyramidal tubercle; at 

 the anterior part of the crown ; and at the posterior part of the latter, in which 

 position it forms an angular process. 



The first inferior molar, as indicated in the specimen by a single fang which it 

 possesses, is a much smaller tooth than any of those in the series posterior to it. 



The species is named in honor of Prof S. P. Baird, of the Smithsonian Institution. 



MEASUREMENTS. 



Inches. Lines. 



Lengtli of cranium from summit of inion to anterior extremity of ossa frontis 4 8 



Length from occipital condyle to anterior orbital margin .... 4 



Length of temporal fossa . . . . . • • • • . o U 



Length of sagittal crest ......••••-'- ' 



Length of ossa frontis ....■•■■•• ^ •* 



Height of inion ......•■••■• ^ ° 



Height of face at last molar alveolus . . • ■ ■ • • . ^ ^ 



Height of orbit from floor to supra-orbital margin 1 " 



Breadth of cranium at para squamosse ...••••• •^ 



Breadth of forehead at anterior orbitar processes ....•••'■■'■" 



Breadth at paramastoids ....••••■• 



Breadth at post-glenoid tuberosities ..■•■■■• ■^ * 



Breadth of hard palate at sixth molares ..■■■■• ^ " 



Height of body of lower jaw at last molar ..•■•■•■'■ 



Height of body of lower jaw at second molar . . • • • . v it 



Length of upper normal series of molars . . • ■ • • • ^ 



Length of lower normal series of molars ...•••• ° 



Antero-posterior diameter fourth upper molar ...■••" 



Transverse diameter fourth upper molar ^ ' * 



Antero-posterior diameter fourth lower molar ^ " 



Transverse diameter fourth lower molar " ** 



Antero-posterior diameter last lower molar " ' 



