49G ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



ered with long- hair, contrary to what is seen in the other 

 gorillas, in which the skin of this region is denuded and sim- 

 ply covered with short and worn hairs." The hairiness of 

 the back is supposed to indicate a difference of habits, and 

 that the new form does not repose, like the common gorilla, 

 against its back, but is more arboricolar, like the chimpan- 

 zee. Although such differences as those recorded are in- 



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teresting, the species cannot be considered to be well es- 

 tablished, and, like the considerable number of others of the 

 gorilla and chimpanzee types that have been proposed from 

 time to time, must be considered as at least doubtful, till a 

 very critical examination of much more material than is yet 

 available can be made. At present, it seems best to admit 

 only two species of African apes Mimetes troglodytes (the 

 chimpanzee) and Gorilla savagei (the gorilla). Whether 

 the differences observable in specimens of those generic types 

 are of specific, varietal, or only individual value, remains yet 

 to be ascertained. 



Chronological Paleontology of the Vertebrates. 



Much activity has been manifested in investigations of the 

 Vertebrates of the different ^eolosncal horizons; the most ac- 



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tive in this country during last } 7 ear, as in those preceding, 

 having been E. D. Cope and O. C. Marsh. Abstracts of sever- 

 al memoirs and communications of special interest are given; 

 but, perhaps, quite as important as these are the researches 

 of the gentlemen just referred to, on the reptiles of the Per- 

 mian epoch; a memoir, by Cope, on some Fishes of the "No. 

 3" Cretaceous beds of Dakota; and articles, by Messrs. Cope 

 and Marsh, on gigantic Saurians of the Dakota Rocks of Col- 

 orado. A "Paleontological Report of the Princeton Scientific 

 Expedition of 1877," by Henry J. Osborn, Win. 13. Scott, and 

 Francis Speir, Jr., may be also specifically mentioned, on ac- 

 count of the discoveries therein recorded, as also for the rea- 

 son that it contains a full systematic catalogue of the Eocene 

 Vertebrates of Wyoming. 



The Dipnoous a Predominant Type of the Palaeozoic Age. 

 It will be remembered that the order of Protopterl is repre- 

 sented, in the present epoch, by only three fresh-water gene- 

 ra, (1) Protopterus, of Africa; (2) Lepidosiren, of South Amer- 



