THE IMPORTANT FACTS 



461 



is in the neighborhood of the nasal capsule^ originating on the ventral 

 side of the paraseptal cartilage. The vomer in Dicijnodon certainly ap- 

 pears to be a paired bone, and its relationships are like those in the 

 mammals. The rostrum of the basis cranii I could not imagine as being 

 the mammalian vomer. 



MTrCfi 



Figure 2. — Dicynodon sollasi Broom from below. Natural size. 



Bo = Basioccipitale. 



Bs = Basisphenoid. 



Ch = Internal nares. 



Eo = Exoccipitale. 



Ep = Epipterygold. 



F. c. = Foramen carotidls. 



F. p. = Foramen parietale. 



F. V. =: Fenestra vestibuli. 



F. V. = Foramen vagi, etc. 



J = Jugale. 



I. Pt. := Interpterygoidal space. 



L = Lacrymale. 



M = Maxilla. 



N = Nasale. 



Opo = Opisthoticum. 



P = Parietale. 



Pa = Parasphenoid. 



PI = Palatinum. 



Pm = Prsemaxilla. 



Po = Postorbitale. 



Pof = Postf rontale. 



Prf = Prsef rontale. 



Pro = Prooticum. 



Ps = Praesphenoid. 



Pt = Pterygoid. 



Q = Quadratum. 



Qj = Quadratojugale. 



Sm = Septomaxillare. 



Sq = Squamosum. 



T. Bo. = Tuber basioccipitale. 



Tr. = Transversum. 



V = Vomer. 



Z = Tooth. 



The distribution of the bones on the ventral side of the skull of 

 Dicynodon (and also of all Theromorpha) does not differ greatly from 

 that of the same region in the later reptiles, the Archosauria, as well as 

 in the Stegocephalia and also in the mammals. Some of the earlier de- 



