424 PKOF. OYfEX ON AN ANOMODONT EI^TILE PEOM 



the suborder Anomodontia, to resemble that of the Mammals, and,, 

 as I have pointed out, especiall}^ that of Echidna " (p. 1). 



In the pelvis of Dicynodon tigriceps, described and figured in my 

 'Descriptive and Illustrated Catalogue of the Possil Eeptilia of 

 South Africa ' *, the sacrum includes six ankylosed vertebrae, and 

 the expanse of the iliac bones resembles that in many placental 

 mammals ; whereas in Echidna the ilia are strong but narrow 

 three-sided columns, and the sacral vertebras are but three in number. 

 The chief pelvic characteristic in that Monotreme is in the marsupial 

 bones, which exceed the ilia in length. I have not detected any 

 evidence of these bones in the South-African reptilian fossils whicli 

 I have hitherto examined. The particulars of the monotrematous 

 characters of the scapular arch and humerus are not given ; nor are 

 any figures of the subjects of Professor Cope's paper appended 

 thereto ; but the author states (p. 22) "that they will appear in the 

 Proceedings of the American Philosophical Society." The discovery 

 of the fossil marsupial bones in the pelvis of the Permian Eeptile 

 will be one of much interest. 



[EXPLANATION OF PLATES XVI. & XYIL 

 Plate XVL 



Plafypodosaurus robusius. 



Pig. L Two dorsal vertebrte, vertically and longitudinally bisected, in outline : 

 f natural size. 



2. Transverse vertical section of middle of centrum, in outline: f nat. 



size. 



3. Side view of a dorsal vertebra : f nat. size. 



4. Yertieal longitudinal section of two dorsal vertebrse oi Echidna hydrix : 



nat. size. 



5. Foremost sterneber : \ nat. size. a\ anterior articular surface ; V, 



lateral articular surface ; & , posterior articular surface. 



6. Sternum of Ornithorhynchis paradoxus : nat. size, a, a', anterior arti- 



cular surface ; b, b', lateral articular surface ; c, c\ posterior articular 

 surface. 



7. Humerus ; rather more than ^ nat. size. 



8. Humerus of OrmtJiorhynchus 'paradoxus : nat. size. 



9. Humerus of Echidna hystrix : nat. size. 



Plate XYIL 



Fig. 1. Scapula o^ Plafypodosaunis, outer surface; ^ nat. size. 



2. Scapula of IHafypodosaunts, inner surface : ^ nat. size. 



3. ^cn.-^u\n, of Ornithorhynchus paradoxus, oxxieY SYXxincQ-. nat. size. 



4. Scapula of Echidna hystrix, outer surface : nat. size. 



5. Digital bones of the fore paw of Dicynodon (?), outer surface : nat. size. 



6. Proximal part of femur oi Plafypodomurus, fxont surface; 6 a. Trans-- 



verse section of shaft of the same : -| nat. size. 



7. Proximal part of femur of Platypodosatirus, inner border : ^ nat. size. 



8. Proximal part of femur of Tareiasaurus, front surface ; 8f/. Transverte ' 



section of shaft of the same : ^ nat. size. 



9. Femur of Echidna hystrix, front surface ; 9 a. Transverse section of shaft 



of the same : nat. size. 

 9'. Femur of Echidna hystrix, inner border : nat. size. 



10. Portion of right mandibular ramus and molar teeth of Ornithorhynchits 



paradoxus : nat. size. 



11. Portion of right mandibular ramus and molar teeth of Placodus Meyeri : 



-J nat. size. 



* 4to, 1876, pp. 40, 41, pis. xxxvi. & xxxvii. 



