238 THE UNIVERSITY SCIENCE BULLETIN. 



It seems, therefore, that the supraoccipital was present in 

 Eryops, but that in adult hfe the element was fused with the 

 exoccipitals. Its presence would be logically expected, since the 

 postparietal is clearly excluded from the foramen magnum. To 

 have the two exoccipitals meet and fuse above would be decidedly 

 unusual; and even if no trace of sutures were to be found, it would 

 be logical to interpret the upper part as supraoccipital and the 

 lateral as exoccipital. The old assumption that the supraoccip- 

 ital is absent in the Amphibia can not be given any considera- 

 tion, for the writer has made it out in Trematops, and it will prob- 

 ably be found in other Temnospondyli when looked for. 



Von Huene (1912) supposed the supraoccipital to be present, 

 and showed it in his drawings of the occiput. The part he desig- 

 nated as supraoccipital, however, forms less than one-third of the 

 element. 



The palates are poorly preserved in all of the Chicago specimens, 

 from which the matrix had been removed, but as far as their ele- 

 ments could be made out, they agree with the descriptions of 

 Case and Broom. As regards the dentition of the palatine, trans- 

 verse and vomer bones, however, there is difference of opinion. 

 Branson and Broom concluded that each of these bear one large 

 tooth at a time, and explain the cases of two occurring at once as 

 being due to the development of a second tooth, to replace the 

 first, before the first happens to be shed. Case believed that there 

 were normally two on each bone, with which view the writer is 

 agreed. The number of cases in which two teeth are present and 

 indistinguishable as to size or appearance in the specimens at 

 hand, and in published drawings available, seems to show that 

 two is the normal number, and that a less number is due to one or 

 both being lost in preservation. The following table shows the 

 conditions found : 



Number Number Number Number 

 Element. examined. , laying having having 



two teeth. none. one. 



Vomer 16 5 9 2 



Palatine 15 6 5 4 



Transverse 13 4 6 3 



It will be seen that two teeth are preserved about as often as 

 one. These two, it may be mentioned, are similar in size and 

 appearance in nearly every case. The fact that there are so often 

 no teeth at all suggests strongly that these were broken off and 

 lost, either before or after death, but more probably afterwards, 

 and that where only one tooth is present the other has been thus 

 lost. Owing to the large size and prominence of the teeth, a slight 



