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Lyell says Stigmaria & Sigillaria are now found by Brongniart to have much dicotylodenous structure between their latter grand division & Acotyledonous. Osculant groups, are now rare so says Macleay - they may safely said to be less rare in past ages & in proportion to antiquity - not that nearly all old races are osculant.

Owen

Mylodon shows in absence of true dorsal vertebræ relation to [birds]in very slight degree in bones of ear, in cloaca, in one sloth in having 9 cervical vertebræ - in muscular stomach, all show same relation. There seems too many points to be relations of analogy or adaptation, but real relations of affinity — Mylodon has two toes ending in kind of hoof & 3 unguiculate. The sloth has 3 or two with claws & the merest rudiment of other toes (not exactly the analogous ones to Mylodon) Now we can trace gradation of loss from 5 to 3 by Mylodons habits most beautifully

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Some of Mylodons bones no marrow, in others just a trace of it - Apterix narrow in leg bones only bird - so had Dinornis also New Zealand bird - like Dodo lately extinct - Thinking what proofs of subsidence & elevation has subsidence destroyed animals of S. America?

Owen yields to New Red Sandstone birds of America - Mastodontoid animals from Australia, not aquatic, whether Deinotherium or not. Yes - Owen says lungs of Apterix not very unlike those of Crocodile - conjectures the Megalosaurus had perfect circulation, like Birds - Forbes grand fact about fossils becoming rare near their extinction & at first commencement - if this can be proved grand fact - Ophiura found by Sedgwick is lower Silurian genus not known to be older than Lias!!!

Memoranda. Feb. 1843.