356 PB0F. OWEN ON EVIDENCES OP THEK10DONTS IN PERMIAN 



is figured, of the natural size, by Eichwald in pi. lvii. fig. 25, op. 

 cit. In the text of this work the genus Melosaurus of von Meyer, 

 together with the genera Brithopus and Orthopus of Kutorga, are 

 made synonyms of the Eurosaurus of Fischer*: no characters of 

 the Permian humeri are pointed out to show the reptilian nature of 

 Kutorga' s fossils ; but Kutorga's determination of their homology is 

 called in question ; they are affirmed to be portions of the coracoid bone 

 of Eurosaurus ; and the perforations in the bone assigned to Britho- 

 pus are homologized by Eichwald with those in the coracoid of 

 Ichthyosaurus and Hylceosaurus f . 



The three folio plates of Eichwald's ' Lethaea Eossica ' are devoted 

 to the reptilian fossils of the Permian deposits in the Ural. Long 

 bones and portions of long bones are figured, as of Eurosaurus 

 uralensis, but give not any indication of correspondence with such 

 bones from the Karoo beds. 



The characters described and figured of the skull of the Melo- 

 saurus, v. M., are Labyrinthodont. The strong mandible and its 

 canine-like anterior teeth suggest the need of as firm a junction of 

 the head to the trunk as in the Salamandroides of Jaeger {'. Whe- 

 ther the occiput in the subject of v. Meyer's description be in such 

 a state of preservation as to support the conclusion that the basi- 

 occipital had not advanced beyond its embryonic notochordal state, 

 may be worthy of fresh scrutiny of the specimen in the " Mineralien- 

 Kabinet." With whatever result, it would give no support to Eich- 

 wald's reference of Kutorga's Brithopus and Orthopus to such 

 Labyrinthodont genus, or to the synonymy of Melosaurus with 

 Fischer's Eurosaurus. 



The homology and reptilian characters of the portions of Permian 

 fossils described and figured by Kutorga being now beyond question, 

 it is to the Theriodont, not the Labyrinthodont order that such 

 humerus must be referred. I say " Theriodont " rather than 

 "Anomodont," because of the indicatien of the more powerful 

 muscles working the forearm and paw which is afibrded by the 

 degree of development of the "supinator" or " ectocondylar " crest 

 in Brithopus, as in Cynodraco. A minor development differentiates 

 the humerus in the genera Dicynodon and Oudenodon. 



I therefore proceed to seek for other evidences of Theriodontia in 

 Permian fossils of the Ural. 



* Letbsea Eossica, 8vo, 1860, p. 1621. 



t " L'os coracoide " de YEurosaurus " a ete pris 1 ant^rieureruent pour la 

 partie inferieure de l'humerus d'un Mammifere ; il seinble plutot se rapporter 

 a l'os coracoidien de l'omoplate, qui offre une forme tres-large dans Ylchthyo- 

 saurus et surtout dans le Hylceosaurus Mantelli."... "Jjob coracoide de V Hylceo- 

 saurus est perfore d'un trou arteriel et nerveux; le coracoide de YEurosaurus 

 en offre deux, un trou large, perce de chaque cote de sa partie retrecie par 

 laquelle passaient des arteres et des nerfs de l'extremite anterieure." 



" l Kutorga die organ. Ueberreste des Kupfersandsteins, &c. pi. i. fig. 1-3 " 

 (Eichwald, op. cit. p. 1626). " M. Kutorga a decrit un autre os fragmentaire 

 comme ' pars condyloidea humeri ' d'un Mammifere inconnu ; je pref£rerais le 

 nommer aussi l'omoplate, en 1'ajoutant a l'os coracoide " (ib. p. 1626). 



t Fossile Reptilien im Wiirttemberg, 4to, 1828, p. 38, Taf.'v. figs. 1 & 2. 



