PLATE LV. 



Bakenoptera borealis. 



Fig. 1. Skull, norma occipitalis. Twice natural size. 

 Fig. 2. Skull, norma lateralis. Twice natural size. 



1. Interparietal. 



2. Superior fontanelle. 



3. Parietal. 



4. Squamosal. 



5. Zygomatic process. 



6. Postorbital process of frontal. 



7. Optic foramen. 



8. Exoccipital. 37. 



9. Supraoccipital. 



10. Occipital condyle. 



11. Lateral fontanelle. 40. 



12. Otic capsule. 41. 



13. Stylohyal. 42. 



14. Postglenoid process of squamosal. 



15. Hamular process. 



16. Jugular foramen, compartment for vein. 45. 



17. Jugular foramen, compartment for nerves. 



18. Auditory bulla. 47. 



19. External auditory meatus. 48. 



20. Paroccipital process. 49. 



21. Exoccipital ossification centre. 50. 



22. M. semispinalis. 51. 



23. Mm. recti postici. 



24. Mm. recti antici et scalenus. 52. 



25. M. rectus lateralis. 53. 



26. M. obliquus superior. 54. 



27. M. longissimus dorsi. 55. 



28. M. trachelo-occipitalis. 56. 



29. M. depressor mandibulae. 57. 



M. splenius. 



M. trachelo mastoideus. 



M. sternomastoideus. 



M. mastohumeralis. 



Frontal. 



Lachrymal. 



Orbital process of maxilla. 



Descending process of frontal. 



Ala orbitalis. 



Palate. 



Internal pterygoid. 



External pterygoid. 



Ala temporalis. 



Sphenoidal fissure. 



Maxilla. 



Transverse rostral muscle, superficial layer. 



Transverse rostral muscle, deep layer. 



Retractor naris. 



Oblique narial muscle. 



Nasal bone. 



Premaxilla. 



Insertion of deep stratum of occipito-frontalis and of 



supra-orbital muscle. 



Attachment of ligamentum apicis dentis. 



Origin of supraorbital muscle. 



M. masseter. 



M. sternomandibularis. 



Septal cartilage. 



M. temporalis. 



