762 
PROFESSOR OWEN ON THE MEGATHERIUM. 
Fig. 26. Back view of a middle trunk-vertebra of the Python Sehve, 
Fig. 27 . Under view of ditto. 
Fig. 27 '. Vertebral ribs or ‘ pleurapophyses ’ of the Python. 
Fig. 28. Front view of a middle tail-vertebra of ditto. 
Fig. 29. Side view of a middle trunk-vertebra of the Coluber elaphus. 
Fig. 30. Front view of ditto, with one of the ribs. 
Fig. 31. Back view of ditto. 
Fig. 32. Under view of ditto. 
Fig. 33. Side view of a middle trunk-vertebra of the Hydrus hicolor. 
Fig. 34. Side view of a middle trunk-vertebra of Naja. 
Fig. 35. Back view of ditto. 
Fig. 36. Side view of two middle trunk-vertebrm of the Crotalus durissus. 
Fig. 37 . Back view of ditto. 
Fig. 38. Front view of ditto. 
Fig. 39. Under view of ditto. 
Fig. 40. Side view of a middle trunk-vertebra of the Iguana. 
Fig. 41. Front view of ditto. 
Fig. 42. Back view of ditto. 
Fig. 43. Under view of ditto. 
Fig. 44. Side view of a middle trunk-vertebra of the Palceophis typhoeus. 
Fig. 45. Front view of ditto. 
Fig. 46. Back view of ditto. 
Fig. 47 . Under view of ditto. 
The same letters indicate the same parts in each figure : — 
c. The centrum. 
d. The diapophysis, its articular tubercle. 
d'. Its inferior production. 
d". Its superior production. 
The anterior zygapophysis. 
z'. The posterior zygapophysis. 
ns. The neural spine. 
n. The neurapophysis, produced into an angle in Palceophis. 
pi. The pleurapophysis. 
zs. The zygosphene. 
za. The zygantrum. 
hy. The hypapophysis. 
PLATE LII. 
Fig. 48. The five last cervical and five first dorsal vertebrae of the Great Penguin 
{Aptenodytes patachonica): an under view, showing the great development 
and metamorphoses of the hypapophyses (h). 
