148 



ESSAY ON CLASSIFICATION. 



traits of the animal kingdom, it is necessary for me to 

 make a few more remarks upon this topic. I can, fortu- 

 nately, be very brief, as we possess a text-book of Palae- 

 ontology, arranged in zoological order, in which every one 

 may at a glance see how, throughout all the classes of the 

 animal kingdom, the different representatives of each, in 

 past ages, are distributed in the successive geological for- 

 mations. 1 From such a cursory survey it must appear 

 that, while certain types prevail during some periods, they 



malia and Chelonia from Nebraska 

 Territory, iu D. I). OWEN, Geol. 

 Surv. of Wisconsin, Iowa, Miuesota, 

 etc., Philadelphia, 1852, 4to. fig. 

 On Bathyynathus borealis, an ex- 

 tinct Saurian, Journ. Ac. Nat. Sc., 

 Philad., 1854, 4to. fig. Description 

 of a New Species of Crocodile, etc., 

 Ibid., 1851. WYMAN (JEFFU.), On 

 some remains of Batrachian Reptiles 

 discovered in the Coal Formation of 

 Ohio, Amer. Journ., 1858, vol. 25, p. 

 158. Birds: OWEN (R), History of 

 Bi'itish Fossil Mammalia and Birds, 

 London, 1844-46, 1 vol. 8vo. fig. 

 Fossil Birds from the Wealden, 

 Journ. Geol. Soc., II., p. 96. Me- 

 moir on the Dinornis, Trans. Zool. 

 Soc., vol. 3, p. 3, London, 1844, 4to. 

 fig. Mammalia: CUVIEB (G.), Oss. 

 foss., q. a. BUCKLANB (W.), Rel. 

 Diluv., q. a., p. 142. DE BLAINVILLE 

 (DucR.), Osteographie ou Descrip- 

 tion iconographique comparee du 

 Squelette, etc., Paris, 1841, et suiv. 

 4to. Atlas fol. KAUP (J. J.) De- 

 scriptions d'ossemens fossiles de 

 Mammiteres incounus, Darmstadt, 

 1832-39, 4to. fig. OWEN (R.) Odon- 

 tography, or a Treatise on the Com- 

 parative Anatomy of the Teeth, Lon- 

 don, 1840-41, 3 vols. 8vo. fig. Brit, 

 foss. Mam. and Bii'ds, q. a. The 

 Fossil Mammalia of the Voyage of 

 H. M. S. BEAGLE, London, 1838, 4to. 

 fig. Description of the Skeleton of 

 an extinct gigantic Sloth, Mylodon 

 robustus. London, 1842, 4to. fig.; 

 and many papers in Journal of Geo- 



logical Society ; Trans. Zool. So- 

 ciety, etc. SCIIMERLING (P. C.), 

 Recherches sur les ossemens fossik's 

 des cavernes de Liege, Liege, 1833- 36, 

 2 vols. 4to. fig. CROIZET et JOBERT, 

 Recherches sur les ossemens fossiles 

 du departement du Puy-dc-D6me, 

 Paris, 1828, fol. fig. MEYER (H. v.), 

 Zur Fauna, ete., q. a. Die fossilen 

 Ziihne und Knochen, in der Gegend 

 von Georgensgmund, Frankfurt a. 

 M., 1834, 4to. fig. JAEGER (G. FR.), 

 Die fossilen Saugethiere Wiirtem- 

 bergs, Stuttgardt, 1835-39, fol. fig. 

 FALCONER (H.), and CAUTLEY (P. 

 T.), Fauna autiqua Sivalensis, etc., 

 London, 1846, fol. fig. GERVAIS 

 (P.), Zoologie et Paleontologie fran- 

 gaises, Paris, 1848-52, 4to. fig. 

 MiiLLER ( J.) Ueber die fossilen R,este 

 der Zcuglodonten, etc., Berlin, 1849, 

 fol. fig. LE CONTE (J.), On Platy- 

 gonus compressus, Mem. Amer. 

 Acad. Arts and Sc., 1848, 4to. fig. 

 WYMAN (J.), Notice of the Geolo- 

 gical Position of Castoroides Ohio- 

 ensis, by J. HALL, and an Anatomical 

 Description of the same, Boston 

 Journ. Nat. Hist., 1847, vol. 5, p. 

 385, 8vo. fig. WARREN (J. C.) De- 

 scription of a Skeleton of the Mas- 

 todon giganteus, Boston, 1852, 4to. 

 fol. LEIDY (J.), The Ancient Fauna 

 of Nebraska, Suiithson. Contr., Wash- 

 ington, 1852,4to. fig. See also Sec. 22. 

 1 I allude to the classical work of 

 PICTET, Traite elementaire de Pale- 

 ontologie, q. a., a second edition of 

 which is now being published. 



