PHTLOGENT OF THE PAL.EOGNATH^ AND NEOGNATH^:. 271 



B. Vertebr.e (uot including Cryptiiri) K 

 All the pre-synsacral vertehrre arc lieterocceloiis and free ; all tlie synsacral vertebne develop 

 high neural spines ; iuterceiitra are wanting. 



A. Hyperapopliyses of axis well developed ; cervical vertebrae short ; cervical 

 diapophysial lamellae large and conspicuous ; at least one lumbo-sacral 

 vertebra; sacro-caudal (post-sacral) vertebne well ossified. 



a. Hyperapopliyses of atlas moderate ; neural s[)ine of axis rather high ; 



hyperapopliyses of axis well developed; cervical vertehrse rather short; 

 neural spines of cervical vertebne well developed and greatly excavated 

 postaxially ; no neural spines laterally bifurcating ; catapophyses com- 

 mence at about the sixth vertel)ra, and do not form a ring ; hypapophyses 

 well developed, not much produced postaxiad; diapophysiul himella 

 extending towards postzygapophysis, large and conspicuous ; cervical 

 ribs moderately long and styliform; thoracic and lumbar neural spines 

 not much axially extended, and not subccpud in height ; [lost-sacnd 

 vertebra? raised in part, more or less, aljove ventral margins of aeetabula; 

 sacral vertel)ne not plainly distinct from post-sacrals ; sacral and post- 

 sacral neural spines laterally expanded and separating the post-acetabidar 

 ilium ; caudal vcrtebrse eight or nine; pygostyle cylindrical. 

 a' . Total number of vertebne fifty-four ; cervical vertebr<e seventeen or 

 eighteen; vcrtebrse with ribs nine ; post-sacral vertebrse nine or ten; 

 pre-axial articular surface of atlas moderately notched dorsaliy ; hypa- 

 pophysis of axis much elongated; hypapophyses developed from the 

 eighteenth or nineteenth to the twenty-third vertebra; a conspicuous 

 fossa on each side of the pre-axial part of the neural spines of dorsal 

 vertebrse ; post-sacral vertebne raised decidedly dorsad of ventral 



margins of aeetabula Dromeens. 



b'. Total number of vertebne from fifty-five to fifty-nine ; cervical vertebraj 

 fifteen or fourteen ; vertebrae with (free) ribs eleven or twelve ; sacro- 

 caudal (post-sacral) vei'tebrre eight or nine; pre-axial articular surface 

 of atlas moderate, may become a foramen ; hypapophysis of axis 

 extremely long; hypapophyses developed from eighteenth to twentieth 

 vei'tebra; fosste be>ide pre-axial part of neural spines very small ; sacro- 

 caudal (post-sacral) vertebr;i raised scarcely at all dorsad of aeetabula . Casuarius. 



b. Hyperapopliyses of atlas large ; neural spine of axis lofty ; hyperapophysis 



of axis moderate or extremely large ; cervical vertebras short ; neural 

 spines of cervical vertebrae generally more or less well developed ; cata- 



resembles D, irroratus. In the conspieuous development of the cerebral dome it differs from both existinjf 

 species. 



I would remark here that the specitic characters attributed to D. irroniliis are bated upon an cxaminatiou 

 of a single unnamed skull in the British Museum Collection ; but these appeared to me to be suihciently 

 marked to justify my determination of this skull as of D. irroratus. 



' This Key is compiled, with modifications, from Mivart's memoir. 



2p 2 



