[128] The sub-genera Halmaturus and Heteropus, Osphranter, Lagorchestes, and Petrogale, are included in Macropus, and many other sub-genera relating to the other families merely complicate the classification. Bettongia, Potoroiis, are sub-genera or artificial groups of the genus Hypsiprymnus; Cuscus, Trichosurus, Pseudochirus, and Dromicia, are groups of Phalangistidæ; Petaurista, Belideus, and Acrobata are divisions of the genus Petaurus; Macrotis is a sub-genus of Perameles; Antechinus is a division of the genus Phascogale; Sarcophilus is a sub-genus of Dasyurus. These are unnecessary sub-divisions.
[129] μόνος, one; τρῆμα, opening.
[130] Echidna hystrix (Cuvier). Much confusion has been produced by Illiger, who changed the generic title to Tachyglossus, ταχύς, quick, and γλῶσσα, tongue; but the name given by Cuvier must stand, except in the minds of those zoologists who delight in novelties, and believe that the use of long words carries wisdom. Lately more confusion has been produced by the introduction of the generic term Acanthoglossus, which we do not admit or use.
[131] Ornithorhynchus anatinus.
[132] Dr. Brehm: “Bird-life,” pp. 503, 504.
[133] Huxley, “Anatomy of Vertebrates,” p. 274.
[134] παλαιός, old; ἄρκτος, north: i.e., the northern division of the Old World.
[135] νέος, new; ἄρκτος, north: i.e., the northern division of the New World.
[136] νέος, new; τροπικός, tropical: i.e., the tropical division of the New World.
[137] Dr. Sclater, F.R.S., originated, in 1858, this scheme of the six zoogeographical divisions of the globe.