SCOTT : LITOPTERNA OF THE SANTA CRUZ BEDS. 



149 



ment of mandible (No. 15,378) with dps and 4 and the alveolus of my, is 

 probably referable to it, as is indicated by the unusual shallowness and 

 thickness of the horizontal ramus. 



Measurements. 



Dp^, length 024 



" width 010 



Dpj, length 026 



" width 012 



In construction, these teeth display no noteworthy differences from those 

 of T. lallenianti. 



The skull, which in the type-specimen has suffered some distortion and 

 dorso-ventral flattening from pressure, differs from that of T. lallemanti 

 in a number of significant details. The cranium is shorter, the brain-case 

 more rounded, and the sagittal crest is shorter and the anterior sagittal 

 area is narrower ; the nasal processes of the frontals are very much more 

 developed, especially in transverse width, and widely separate the nasals, 

 which are not in contact with each other at any point. The nasals them- 

 selves are considerably shorter than in the preceding species and are 

 attached for their whole length to the maxillaries, not projecting freely 

 beyond them, as they do in T. lallemanti. The free dorsal border of the 

 maxillaries is thinner and less rounded and anteriorly these bones send 

 out processes between the premaxillaries, almost excluding the latter from 

 forming any part of the narial opening, while in T. lalleinaiifi they are 

 more extensively concerned in bounding the opening. Finally, the hori- 

 zontal ramus of the mandible is distinctly more shallow in the dorso- 

 ventral dimension than in T. lallemanti and has a thicker and more 

 rounded ventral border. If the very young mandible above mentioned (No. 

 15,378) be properly referred to T. garrettornm, then the difference in the 

 character of the ramus is even more marked in the young than in the adult. 



Owing to the crushing to which the skull has been subjected, not many 

 measurements can be profitably given. 



Skull, length in median basal line 

 " " cond. to prmx. . 



" extreme length 

 Cranium, length to ant. rim of orbit 

 Face, length orbit to prmx. 



Measurements. 





.323 Occiput, width at base . 



.079 



.339 Nasals, length 



.047 



.349 Mandible, depth below p^ 



.028 



. .177 " " " m^ • 



•033 



.179 " height of condyle . 



.081 



The skeleton has been very fully described in the account of the genus 



