378 CONTRIBUTIONS TO THE OSTEOLOGY OF BIRBS. [Apr. 9, 



X. Key. 



The following " Key " gives the cranial characters of the 

 Families dealt with in this paper. 



Suborder OLIGOMYODI. 



Maxillo-palatines triangular ; vomer truncated ; nasal septum partly ossified ; 

 post-orbital process reduced ; processus zygomaticus squamosi large ; qu^adrate 

 with a lateral pillar for articulation of the quadrato-jugal bar; a shallow 

 temporal fossa extending as far back as the middle of the lambdoidal ridge. 



TiiranniclcB. 



Maxillo-palatines in the form of broad linguiform plates sending up a slender spur 

 into the lachrymo-nasal fossa ; anterior palatal foramen nearly closed ; maxilla 

 with txibei'cles along the tomium ; post-orbital process obsolete ; processus 

 zygomaticus squamosi greatly developed ; quadrate with a vertical, lateral pillar 

 for articulation of quadrato-jugal bar Fhytotomidce. 



Maxillo-palatines in the form of laminate spurs; vomer large, and deeplj' cleft 

 posteriorly ; post-orbital process small ; processus zygomaticus squaraosi large ; 

 nasal septum ossified : beak with a nasal hinge ; temporal fossse separated by a 

 moderatelj' broad sagittal crest Fittida. 



Suborder DIACROMYODI. 



Group I. HiEUNDINES. 



Maxilla passing abruptly into the quadrato-jugal bar in the region of the 

 antorbital plates, projecting laterad of the bar in the form of a wide ledge. 

 Maxillo-palatines slender rods with spatulate free ends underlying the 

 vomei'. Nasal fossa large, septum nasi wanting; anterior palatine foramen 

 of great size; external aperture of ear large, oval, directed downwards and 

 outwards. Post-orbital process feeblj' developed Jlimndinidce. 



Group II. MusciCAP^. 



Maxillo-palatines prodirced into flattened bands. Post-orbital process feebly 

 developed, low down, and separated by a notch from the processus 

 zygomaticus squ.amosi which is feebly developed. Temporal fossa greatly 

 reduced or wanting. 



a. Nasal septum ossified llnscicapidce. 



j3. Nasal septum wanting 



a'. Post-orbital process prominent; maxillo-palatines 



with hastate free ends CampopliagidcB. 



j5'. Post-orbital process obsolete; maxillo-palatines 



with spatulate free ends Vireonidce. 



Oroup III. Lanii. 



Maxillo-palatines in the form of short, more or less triangular spurs with a 

 palatal vacuity. 



a. Post -orbital process feebly developed; processus 

 zygomaticus squamosi large ; nasal septum stronglj' 

 developed Laniidee. 



j8. Post-orbital process well developed ; processus z3'go- 

 maticus squamosi large; nasal septimi imperfect; 

 maxillo-palatines embracing facets on the vomer ... llalaconotidce. 



y. Post-orbital process well developed ; processus zygo- 

 maticus squamosi moderately large; nasal septum 

 well developed ; maxillo-palatine processes embracing 

 facets on the vomer Dicruridee. 



c. Post-orbital process well developed ; processus zygo- 

 maticus squamosi obsolete; nasal septum nearlj' 

 fitting palatal vacuity Frionopidce. 



6. Post-orijital process obsolete ; processus zygomaticus 

 squamosi large, conical; nasal septum feebly ossified ; 

 palatal vacuity nearl}' filled by septum nasi, and 

 longitudinal osseous bar forming floor of vestibulum. Ct/dorhidcs. 



