No. 582] RECENT STUDIES ON FOSSIL AMPHIBIA 371 



line organs which were imperfectly studied some years 

 ago 3 by the reviewer; so it is yet too soon to say that 

 every detail of structure is known. The palate is very 

 completely known and is figured by Broom. He has fig- 

 ured also very imperfectly, but for the first time, sections 

 through the ear and brain-case showing the probable size 

 of the dural cavity. He says that the portion of the par- 

 occipital which lodges the labyrinth was cartilaginous, but 

 does not give his reasons for this statement. In view of 

 the almost perfect preservation of the semicircular canals 

 in fishes, eotylosaurs and pterodactyls we should expect 

 a favorably preserved specimen of an amphibian to show 

 this structure also. He describes a pit in the basisphe- 

 noid for the reception of the hypophysis. He also figures 

 for the first time the complete osteology of the mandible 

 of Eryops. The author likewise describes and briefly 

 figures two new species of stegocephalians. The same 

 author (4) has given considerable attention to the study 

 of the osteology of the mandible in TrimeorohacMs, the 

 discussion being very similar to that given in the above 

 paper. The discussion has especially in view the problem 

 of the derivation of the Amphibia from the Crossopte- 

 rygia, and he figures the mandible, shoulder girdle and 

 pectoral fin of Sauripteris taylori on account: 



resembling the tetrapod limb than in any" othe/known form. 



Case (5) reviewed before the American Paleontological 

 Society the recent trend of studies on the air-breathing 

 vertebrates of the Paleozoic. He states there are two 

 general conclusions which have been reached by students 

 of these early vertebrates. First, Baur initiated the idea 

 of the crossopterygian ancestry of the Amphibia, and 

 later workers have so far confirmed his suggestion as to 

 make it extremely probably that the land vertebrates arose 

 from these fishes. The intermediate stages are unknown. 

 The second conclusion is 



that the primitive reptiles— the Cotylosauria— were derived directly 

 from the Stegoeephalia. . . . 



So we are thus in possession of partial proof at least of 



*Journ. MorphoL, 1908, Vol. XIX, p. 511. 



