PLATE XXIII. 



FIG. 

 1. 



3. 



4. 



5. 



6. 



7. 



8. 



9. 

 10. 

 11. 

 12. 



13. 

 14. 



15. 

 16. 

 17. 

 18. 

 19. 

 20. 

 21. 

 22. 

 23. 



24. 



25. 



26. 



Do. 

 Do. 

 Do. 

 Do. 

 Do. 



Tatusia pelia 1 (ripe embryo). Right scapula, outer, and Sternum, inner 



view .... 

 Base of scapula ; outer view 

 1st left rib ... 



6th right rib . 



do. . 



Section of fore-part of Sternum . 

 Fore-part of Sternum ; upper view 

 Posterior surface of 1st mesosternal joint . 

 Joint of middle rib 

 Last rib but two 



do. three .. 

 Euphractus villosus* (ripe embryo). Right scapula, outer, and Sternum, 



inner view . 



(do.) Prae-coracoid and omosternal 



(do.) Free surface of 1st mesosternal, and 



section of sternal ribs . 

 Last mesosternal and xiphisternum 

 Ideal section of prae-steruum 

 Orycteropus capensis 6 (old). Right scapula and clavicle ; outer view 



Do. (do.) Clavicles and fore-part of Sternum ; outer view 



Do. (do.) Ideal section of mesosternal 



Do. (do.) Xiphisternum ; outer view 



Myrmecophagajubata 1 (adult). Right scapula; outer view 

 Tamandita bwittata* (three-fourths adult.) Fore-part of thorax ; outer view . 

 Do. (do.) Hinder part of Sternum ; outer 



(two-thirds adult), 

 (do.) 

 (do.) 



(very old), 

 (ripe embryo). 

 Do. (three-fourths adult). 

 Do. (do.) 



Xenurus unicinctus z (old). 

 Dasypus sezcinctus 3 (adult). 

 Do. (do.) 



Do. 

 Do. 



(adult). 

 (do.) 



Do. 



Do. 



Do. 

 Do. 



(do.) 



(do.) 

 (old). 



view 

 A mesosternal segment, 9 with 



lower heads of sternal ribs ; 



outer view 

 Three mesosternals, with heads of 



sternal ribs ; side view 

 Xiphisternum 



SIZE. 



2^ diam. 



nat. size. 



do. 



do. 



do. 



5 diam. 

 1 do. 



2 do. 

 nat. size, 

 do. 

 do. 



2 diam. 



6 do. 



3 do. 



^ nat. size. 



do. 



ido. 



do. 



nat. size. 

 | do. 

 do. 

 nat. size. 



do. 



4 diam. 



do. 

 nat. size. 



1 See pp. 205207. 

 6 See pp. 205207. 



' See pp. 205 207. 3 See pp. 205207. * See pp. 205 207. 

 See pp. 202, 203. 7 See p.204 . 6 See pp. 204, 205. 



9 In figs. 24 and 25, from above and laterally, the parts are drawn in a diagrammatic manner, 

 and tlie head of the sternal rib in fig. 25 is pushed downwards ; in fig. 24 the upper heads of a pair of 

 ribs are shown attached behind a mesosternal segment ; but they converge too much in the figure, 

 and lie in reality on a much lower plane than the upper surface of the sternal segment (see fig. 25). 



