422 PEOr. T. JEFFEKY PARKER ON THE CRANIAL OSTEOLOGY, 



Subfamily E m e i N ^. 



Width of cranium at paroccipital processes less than twice length of basis cranii. 

 Distance between optic foramina less than one third length of basis cranii. 

 Orbit evenly curved or slightly sinuous (right-angled in Pachyornis, species a). 

 Greatest length of premaxilla rarely more than twice, and never more than two and 



a half times length of basis cranii. 

 Body of premaxillse bluntly rounded in front ; its length always less, its breadth 



either less or slightly more than length of basis cranii. 

 Maxillary process of nasal represented by a distinct maxillo-nasal bone. 

 Maxillo-palatine devoid of an antrum. 

 Mandibular symphysis bluntly rounded ; its width at least three fourths of length of 



basis cranii. 

 Length of mandible usually more than three and less than three and a half times 



length of basis cranii. 



Genus Emeus. 



Occipital plane inclined backwards ; occipital condyle hidden in a view from above 



by supraforaminal ridge, and in a view from the side by paroccipital process. 

 Occipital crest prominent ; supraoccipital fossae well marked. 

 Anterior and posterior lambdoidal ridges distinct, but close together. 

 Width of cranium at paroccipital processes usually about once and a half, but 



occasionally (in E. crassus) once and three quarters length of basis cranii. 

 Width at squamosals rarely more than double length of basis cranii. 

 Mamillar tuberosities large. 



Temporal fossae small ; distance between temporal ridges but little less than width 

 of cranium at temporal fossae ; width of temporal fossa usually about half length 

 of basis cranii. 

 Temporal and lambdoidal ridges do not touch; mid-temporal ridge usually well 



marked. 

 Posterior temporal fossa narrow ; inferior temporal ridge strong. 

 Zygomatic process long, often bifid. 



Postorbital process evenly curved, sometimes slightly inturned at distal end. 

 Antorbital thin ; supraorbital fenestra small ; no definite postchoanal bar. 

 Nasal process of premaxilla very thick, its anterior end not flattened but rod-like ; 



prenarial septum often obscure. 

 Maxillo-jugal arch strong and nearly straight ; maxillo-palatine gives oif dorsally 

 an oblique vertical plate, with sometimes the merest vestige of an antrum at 

 its base. 



