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PROFESSOR OWEN ON THE MEGATHERIUM. 
dorsal, and are reduced to mere tubercles on the third lumbar. In the Civet {Viverra 
Civetta) and the Genette {Viverra Genetta) the anapophyses begin to be developed 
on the tenth dorsal, and continue to the penultimate lumbar vertebra. 
In the Otter {Lutra vulgaris), with d\A, lb, the metapophyses begin to be de- 
veloped on the twelfth dorsal vertebra, and are continued throughout the lumbar 
series ; they are low and obtuse. The anapophyses commence at the eleventh vertebra, 
and are continued to the penultimate lumbar. 
In the Sable {Mustela zihellina), with d 14, Z 6, the anapophyses are present from 
the ninth dorsal to the penultimate lumbar inclusive. 
The Kinkajou, Cercoleptes caudivolvulus, with the same number of true vertebrae 
as the Sable, has the same disposition cf the anapophyses. 
In the Mydaus meliceps, with d\A, IQ, anapophyses are present only on the two 
last dorsal and first lumbar vertebrae : whilst in the Badger {Meles Taxus), with 
d 15, lb, they are present on the first three lumbar vertebrae. 
In the labiated Bear {Ursus labiatiis), with d 15, lb, the met- and an-apophyses 
are distinct on the twelfth dorsal, diverge and increase on the succeeding dorsals, the 
metapophyses continuing throughout the lumbar series, the anapophyses, after under- 
lapping the prozygapophyses of the first and second lumbar, rapidly subsiding. 
In the Saw-toothed Seal {Leptonyx serridens), with d \ b, I 5, the metapophyses 
commence as tubercles outside the prezygapophysis on the second dorsal, are distinct 
on the third dorsal, pass on the fore-part of the diapophysis in the fourth, and con- 
tinue rudimental as far as the tenth dorsal, on which they are well and distinctly 
developed (Plate XLVL, fig. 8, m) ; they again pass upon the outside of the prozygapo- 
physis in the eleventh and twelfth dorsals, and so continue throughout the lumbar, 
sacral, and anterior caudal vertebrae. The anapophyses are mere rudimental pro- 
jections from the back part of the diapophysis (fig. 8, a a). 
Order Rodentia. 
In the skeleton of the common Squirrel {Sciurus vulgaris), with d 12, Z6, may well 
be discerned the progressive metamorphosis, in the last six dorsal vertebrae, of the 
common accessory tubercle upon the diapophysis into the metapophysis and anapo- 
physis, which distinctly coexist with the diapophysis in the ninth dorsal : the diapo- 
physis subsides to a feeble ridge in the three following dorsals, but reappears and 
rapidly increases in the lumbar series ; in the last two of which the anapophyses are 
suppressed. 
In the Malabar Squirrel {Sciurus maximus), with c?13, Z6, the ridge above the di- 
apophysis of the seventh dorsal rapidly expands in the succeeding ones, divides in the 
tenth into metapophysis and anapophysis, which become more distinct in the eleventh, 
and are so continued throughout the lumbar series. 
In the Marmot {Arctomys Marmotta), with d\2, l^J, the accessory tubercle appears 
upon the diapophysis of the ninth dorsal, and divides in the tenth, in which the di- 
