8 



CAI.IFUKMA ACADK.MY dl' SCI l'..N( 'KS 



A fourtli skull, t lie type of 7: iicrriiii , sIkiws the iiivatcr part of the inaiidihU', 

 maxillary ami palatine, with poilioiis of miiiu'roiis other elements of the skull. 



The type of the ^enus Xcrtumnrns consists of the posterior two thirds of a 

 niandihli' with the frontals, parietals, a prefontal, a post-fronto-orbital and part 

 of a (|uadrate. Several loose jaws, portions of skulls, vertebrae, ribs, etc. are 

 also I'eferi'ed to this u'enns. 



GENERA b SKELETAL STRUCTURE. 



Skull. 



I'l.ATES I-VI. 



Considerable p)arts of tin- head are shown in live speeimens. In all of 

 this material, excejjting the type of 'rhahitlo.mKrits, the skulls are small and the 

 bones thin and diflfieult to prepare. 



The skull in the type specimen was fortunately broken into four segments 

 by wide vein-Hlled cracks. In pi'eparation, tlu'se segments were separated so as 

 to show all sides of the bones and the cross-sections of the skull. The sections 

 have been of espec-ial value, serving as checks in observations on the position 

 and arrangement of the bones. 



The restorations of the skull (Text tigs. 1 and 2, and 1*1. vi) were leased on 

 the type specimen. The temj)oral and fronto-parietal regions and a portion of 

 the mandibk' are restored from T. xliasteii-'^i.'i. 



Fig. 1. TJuilaltiixamns ((luKndrni'. Kccniistnu-tril sUull, lateral view, X ^g. Tin, pixMuaxillarv ; 

 .1/, maxillary ; -V, nasal; 7:.', siipfrinr naivs ; /•', frniital ; /'i-, iiarirtal ; /'/', pi't'l'i'diital ; /V", i"ist-fr(iiitii-(ri-liital ; 

 J, jugal ; X, lachrviiial ; /'?, palatim' ; iSc, sclcrntir riii>.'; N/, si|uaiiiiisal ; 'i', (nunlrati/ ; . I/-, articular ; N'l, supra- 

 angulav; ,1//, angular ; T^, dentary. 



Facial Rcj/idii. — As is shown in J'late i, the facial region of this skull is very 

 slender. The snout was narrow, exhibiting some resend>lance to that of the 

 long-headed Mosasaurs. 



