| ete 
it Prof. Owen on the Class Mammalia. 179 
separation as distinct bones. The orbits have not an entire rim 
of bone. Besides these more general characters by which the 
Lissencephala, in common with the Lyencepbala, resemble Birds 
and Reptiles, there are many other remarkable indications of 
their affinity to the Oviparous Vertebrata in particular orders or 
genera of the subclass. Such, e.g., are the cloaca, convoluted 
t supernumerary cervical vertebre and their floating ribs, 
in the three-toed Sloth; the irritability of the muscular fibre, 
and persistence of contractile power in the Sloths and some other 
and beaver; the prevalence of disproportionate development of 
the hind-limbs in the Rodentia ; coupled, in the Jerboa, with 
confluence of the three chief metatarsals into one bone 
, as in 
birds; the keeled sternum and wings of the Bats; the aptitude 
i the Mammalian series, and in their respective association, 
bee 9 
4% the association of the long-clawed Bruta with the Ungulata,* 
and of the shorter-clawed Shrews, Moles and Hedgehogs, as well 
the Bats, with the Carnivora -+ of the Sloths with the Quad- 
‘mana ;+ of the Bats of the same high order ;§ and of the In- 
* . * . sas 
Mo. Macleay, Linn, Trans, vol. xvi (1833); Gray, Dr. J.E., Mammalia in the British 
Nseum, 12mo, 1843, p. xii 
u 
p. 110. 
ainville, Ostéographie, 4to, fase. 1, p. 47 (1889). 
ure. : 
Prof, Gervais, Zoologie et Paléontologie Frangaise, 4to, 1852, p. 194. 
des Animaux, cc. ; in referring to which, M. Gervais states his mig ik yaa 
ne Edwards, “a mis hors de doute les rapports des Rongeurs avec. les pre 
Ts Mammiferes.”—Avnales des s * ces aturelles, ser. il, yol. 1, p.- ~ L e 
