Theriodonts. 83 



verse palatine bones referred to by Seeley. Trans])alatine or 

 ectopterygoid bones are well developed in the Tlieriocephalians, 

 and in most primitive reptiles, but I have not been able to find 

 any trace of them in any Anomodont or Theriodont. Owing to 

 crushing it is difficult to determine with certainty tlie structure 

 of the posterior pterygoid region and the sphenoidal region. 



The small elongated bone which lies between tliebasi-occii)ital 

 and the quadrate is of great interest. It articulates by its inner 

 end with the l)asi-occipital and possibly also with the basi-sphenoid; 

 and by its outer end with the squamosal and apparently also with 

 the exoccipital and the quadrate. The little bone seems to be 

 hollowed out in the centre. Whatever be the determination of the 

 bone it is evidently homologous with the little hour-glass like bone 

 which occupies a similar situation in the Anomodonts. This bone 

 was originally believed by Seeley to he the " malleus," but in his 

 paper dealing with Cynognathus he expresses the opinion that 

 it is a " rudimentary straight cochlea." As the bone is solid in the 

 Anomodonts it cannot be a cochlea in these foi-ms. Though some 

 doubt still exists I am inclined to the opinion I have previouslv 

 given that the bone is a tympanic. 



The squamosal has a short downward process almost on a line 

 with the little supposed tympanic, and along the fi-ont of this lies 

 the small quadrate, — apparently a small roller-like bone with a 

 convex articulation foj- the lower jaw. It has, however, an upward 

 [)rocess which hts into a groove on the back of the S(juamosal. 

 Tlie articcilar has a transverse articulation apparently of similar 

 length to that of the quadrate. The angular is well shown passing 

 backwards into a hollow in the dentary. The bone which lies on 

 the inside of the dentary in front of the pterygoid process I believe 

 to be the surangular. I cannot be certain of a distinct splenial. 



Pres. by Dr. R. Kannemeyer, Wonderboom, Biirghersdorp. 



Specimen No. 2. — This is the snout which Seeley has \nwW 

 tlie ty[)e of (?) Cynognathus leptorhinus, anddescriljed and ligured 

 (Phil. Trans. Vol. l.SO, B. 1895, p. UO). The circular hole in the 

 upper nasal region which Seeley is inclined to regard as a normal 

 depression for the lodgment of a gland seems to me to be entirely 

 due to crushing. The bones that are seen at the bottom of the 

 depression are douljtless the upper parts of the nasals displaced. 

 The suture between the two bones does not lie directly antero- 

 posteriously, but has been rotated about 30 degrees out of the 



