MOODIE: PERMIAN ANPHIBIA. 237 



by him later it is designated as Pygopterus lucius. In the first 

 part of the second volume of the Fossil Fishes (Poissons fos- 

 siles) , page 10, Agassiz placed this skull in the family Sauroidse 

 as the second species of the genus Pygopterus, with the short 

 description : 'Pygojjtei^us lucius Ag., une tete seulement, dont 

 la machoire superieure est plus allongee. Houille de Saar- 

 briick.' In the same work, part II, page 78, this specimen is 

 designated as the fifth species of Pygopterus, with the descrip- 

 tion, 'une tete avec des dents tres acerees, de la houille de Saar- 

 briick. L'original se trouve au Musee de Stuttgart.' He re- 

 gards the same specimen as the third species on page 162 in the 

 synoptic table of the family Sauroidse arranged in the order of 

 the formations of the Carboniferous which contained Sauroidse. 

 It is also given this place in the general table of fossil fishes 

 which appeared in 1844, page xxxvi." 



Jaeger affirmed the supposition of Agassiz that the speci- 

 men was from Saarbriick, from the similarity of the nodule to 

 those found at that place. He then proceeded to show that the 

 skull described by Agassiz as Pygopterus lucius really shows 

 reptilian characters which Jaeger regarded as intermediate 

 between those of a crocodile and an Iguana. He then compared 

 it with the skull of a young crocodile and also with the skulls of 

 various lizards. He found that the measurements and propor- 

 tions of the skull compare favorably with those of the crocodile, 

 and that the teeth have the form and size of those of a newly 

 born crocodile. The position of the orbit is also identical with 

 that of the crocodile. He made the important observation that 

 the nostrils have the lateral position of the lizards. He then 

 compared the specimen with other known fossil forms, i. e., 

 Zygosaurus, RJmiosaurus and the labyrinthodonts, and found 

 considerable differences. He then made the following interest- 

 ing observations regarding Archegosaurus: "At the meeting of 

 naturalists in Aachen in 1847 Goldfuss described the remains in 

 one of the many spherosiderite nodules, which contained a rep- 

 tile skull, to which he gave the name ArcJiegosam-us. He estab- 

 lished three species for the genus, which he described more 

 fully in a later publication. Only one species of this genus, 

 Archegosaurus clecheni, was described and figured in the 

 Neues Jahrbuch fiir Mineralogie, 1847, Tab. VI, with a line 

 drawing." Jaeger then pointed out in a conclusive manner the 

 identity of Pygopterus lucius with A)-cJiegosau)-us. He re- 



