278 R. L. Moodie — Mason Creek Shales. 



5. Mazonerpeton longicaudatwn, Moodie, 1912. One nearly 

 perfect skeleton. 



(3. Mazonerpeton costatum, Moodie, 1912. One imperfect skele- 

 ton. 



7. Cephalerpeton ventriarmatum, Moodie, 1912. Skull and 

 anterior part of body. 



8. Erpetobrachium mazonensis, Moodie, 1912. Humerus, 

 radius and ulna. 



9. Spondylerpeton spinatum, Moodie, 191 2. 12 dorsal (caudal ?) 

 vertebrae. 



10. JErierpeton branchialis, Moodie, 1912. Impression of man- 

 dibles, parts of body and hyobranchial bars. 



These species have been arranged zoologically according to 

 the following plan : 



Class — Amphibia, Linn6, 1758. 



Subclass — Euamphibia, Moodie, 1909. 

 Order — Branchiosauria, Lydekker, 1889. 

 Family — Branchiosauridae, Fritsch, 1879. 

 Micrerpeton caudatum, Moodie. 

 Eumicrerpeton parvum, Moodie. 

 Mazonerpeton longicaudatum, Moodie. 

 Mazonerpeton costatum, Moodie. 

 Order — (?) Caudata, Dumeril, 1806. 

 Family — Cocytinidae, Cope. 

 Erierpeton branchialis, Moodie. 

 Subclass — Lepospondylia, Zittel, 1887. 

 Order — Microsauria, Dawson, 1863. 

 Family — Amphibamidae, Cope, 1875. 

 Amphibamus grandiceps, Cope. 

 Amphibamus thoracatus, Moodie. 

 Cephalerpeton ventriarmatum, Moodie. 

 Family — Molgophidae, Cope, 1875. 

 E'petobrachium mazonensis, Moodie. 

 Subclass — Stegocephala, Cope, 1868. 

 Order — Temnospondylia, Zittel, 1887. 

 Suborder — Embolomeri, Cope, 1885. 

 Family — Cricotidae, Cope, 1884. 

 Spondylerpeton spinatum, Moodie. 



It will be seen from the above arrangement that nearly all 

 of the orders of extinct Amphibia are represented in the 

 Mazon Creek fauna. Since these animals are the oldest known 

 land vertebrates of which there are skeletons, and since the 

 beds in which they occur have never received adequate 



