BY K. BROOM. 



557 



In the early mammals the condition was probably very similar 

 to that of the Theriodonts, and this condition is still retained in 

 a few mammals {Ornithorhynclmis, Miniopterus). In the large 

 majority of recent mammals the small prevomers have been 

 replaced by the palatine processes of the premaxillaries. 



The principal modifications of the vomer and prevomer will be 

 readilv seen from the adjoining table : — 



References to Literature. 

 1. — Albrecht, p. 

 2. — Sutton, J. Bland — "Observations on the Parasphenoid, the Vomer 



and the Palatopterygoid Arcade. " P.Z.S., 1884. 

 3. — Turner, W. — " The Dumb-bell-shaped Bone in the Palate of Ornitho- 

 rhynchus compared with the Prenasal Bone in the Pig." J. Anat. 

 and Phys., Vol. xix. 

 4. — Parker, W. K. —"On the Structure and Development of the Skull in the 

 Mammalia. Pt. ii., Edentata; Pt. ii'i., Lisectivora. " Phil. Trans., 

 1885. 

 5.— Howes, G. B. — "On the probable Existence of a Jacobson's Organ 

 among the Crocodilia, &c." P.Z.S., 1891. 

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