476 



THE AMERICAN NATURALIST 



[Vol. XL 



this point of view, attention being paid especially to the "proatlas" 

 which Broom (:03) has described in Gomphognathus and Trira- 

 chodon. It also occurs in the Rhynchocephalia and the Croco- 

 dilia, and Broom predicts that it will yet be fomid in most of the 

 primitive reptilian types. 



Fischer ( :01) has shown that in the embryo of the European mole 

 (Talpa ri(rop(ra) the lateral condyles are confluent around the base 

 of the foramen ma-num, while in the adult they are separate. He 



"The most iinportatU thing to me is the fact that the configuration 

 of the occipital joint in om- mole occupies a sort of intermediate 

 position between the mammals and the Sauropsida." 



From a study of the chondrocranium of Lacerta agilis, Gaupp 

 (:()0) directly supports Osborn. He finds four cram'overtebral 

 connections: a dorso-median (the ligamentum av)icis deiuis), tiie 

 two lateral corresponding with the lateral condyle-, of the niaimnals, 

 and a ventro-methan (the median basioccipital clement of ( )-~l)()rn) 

 which connects the two lateral parts in the Sauropsida. but which 

 is lost in the mammals. However, he is mistaketi in saying (p. 

 403) that a direct articulation of the ventral part of rhc atlas with 

 the ventral surface of the l)asioccipital is lacking in the niaminals. 



for although sue!) ai 



General Adaptation of Condyle.s 



