“Azara[35] says that the Tucutuco may he ‘found every where; provided that the soil be pure sand, and the situation not subject to be overflowed. As these conditions are fulfilled only in certain spots, their warrens are far separated from each other, even sometimes more than twenty-five leagues, without it being possible to conceive how these animals have been able to pass from one place to another.’ The difficulty, I think, is much overstated; for, as I have said, the burrows of the Tucutuco are sometimes made in very damp places, near lakes; so that they certainly might pass over almost any kind of country. But if the _C. Braziliensis_ and _C. Magellanicus_ be considered as one species, as some French authors are inclined to do, then the difficulty will be increased in a very remarkable manner, as we shall be obliged to transport the Tucutuco over wide plains of shingle, and across many great rivers, and an arm of the sea.”—D. POEPHAGOMYS ATER. Poephagomys ater, _F. Cuvier_, Annales des Sciences Naturelles, 2d series, Zoologie, tom. 1. p. 321. June, 1834. Chile, (_September_.) “This animal is generally scarce, but in certain districts, I believe, of an alpine character, it is abundant. It excavates very extensive superficial burrows, no doubt, for the purpose of feeding on the roots of plants, as in the case of the _Ctenomys Braziliensis_, the habits of which have just been described. Horses passing over districts frequented by these animals, sink fetlock deep through the turf. I procured my specimen from Valparaiso, where the country-people called it ‘Cururo.’”—D. OCTODON CUMINGII. Octodon Cumingii, _Bennett_, Proc. of Committee of Science and Correspondence of the Zool. Soc. for 1832, p. 46. —— —— Transactions of the Zoological Society of London, vol. ii. p. 81. Pl. 16. Dendrobius Degus, _Meyen_. Acta Academiæ, c. 1. c. Naturæ Curiosorum, xvi. p. 610. Pl. 44, 1833. Valparaiso, Chile, (_October_.) These little animals are exceedingly numerous in the central parts of Chile. They frequent by hundreds the hedge-rows and thickets, where they make burrows close together, leading one into another. They feed by day in a fearless manner; and are very destructive to fields of young corn; when disturbed, they all run together towards their burrows in the same manner that rabbits in England do when feeding outside a covert. When running they carry their tails high up, more like squirrels than rats; and they often remain seated on their haunches, like the former animals. According to Molina[36] they lay up a store of food for the winter, but do not become dormant. The Octodon is the “degu” of that author: he says that the Indians in past times used to eat them with much relish. These animals appear to be very subject to be piebald and albinos; as if partly under the influence of domestication. GENUS—ABROCOMA.[37]