1026 MR. OLDFIELD THOMAS ON THE [Dec. 15, 
146. Coendou, Lac. 
Mém. de l’Inst. iii. p. 496 (1801). [Syne- 
theres and Cercolabes, F. Cuv. Mém. Mus. 
ix. p. 427 (1822). ] 
B. CH#TOMYIN®. 
147. Chetomys, Gray. 
P. ZS. 1848, p. 21. 
XVI. Chinchillide. 
148. Chinchilla, Benn. 
Gard. Zool. Soc. i. p. 1 (1829). 
149. Lagidium, Mey. 
N. Act. Ac. Leop. xvi. p. 576 (1833). 
150. Lagostomus, Brooks. 
Trans. Linn. Soc. xvi. p. 102 (1828). 
XVII. Dasyproctide. 
151. Dasyprocta, Il. 
Prodr. Syst. Mamm. p. 93 (1811). 
152. Celogenys, F. Cuv. 
Ann. Mus. x. p. 203 (1807). 
XVIII. Dinomyide. 
153. Dinomys, Pet. 
MB. Ak. Berl. 1873, p. 551. 
XIX. Caviide. 
154. Cavia, Pall. 
Mise. Zool. p. 30 (1766). 
155. Dolichotis, Desm. 
Mamm. ii. p. 360 (1822). 
156. Hydrocherus, Briss. 
Régne Anim. p. 116 (1756). 
Suborder Il. DUPLICIDENTATI. 
F. LAGOMORPHA. 
XX. Ochotonide. 
157. Ochotona, Link. 
Beytr. Nat. ii. p. 74 (1795). [Lagomys’, 
G. Cuv. Tabl. Elém. p. 132 (1798). ] 
at first sight difficult to believe that it is really a member of the family at all, 
and not a relative either of Loncheres or Celogenys, as Burmeister suggested. 
But further examination leads me to think that its dental resemblance to 
Loncheres is only superficial, and that its closeness to Coendow in other respects, 
including the identity of the structure of the feet and pterygoid regions, makes 
it best placed as a peculiar subfamily of the Hrethizontide. 
1 Lagomys (1798), as used for the Pikas, is doubly invalid, as it is both later 
in date than Link’s Ochotona, and is preoccupied by Storr’s Lagomys (1780), 
which is a synonym of Arctomys (cf. Miller, Voles, p. 13, footnote 4). 
