104 [June, 



adaptation of animals to certain districts is not merely limited to the individual 

 species. We observe a similar adaptation among genera, entire families, and even 

 whole classes. For instance, all Polypi, Medusae and Echinoderms, that is to say, 

 all Radiata, without exception, are aquatic. That large group of animals has not 

 a single representative upon any part of the surface of the globe, and during all 

 periods of the existence of our earth we find that they have been limited to that 

 liquid element. And they are not only aquatic, they are chiefly marine; but 

 exceedingly few of them are found in fresh waters. Among mollusca we find 

 almost the same adaptation ; their element also is the sea. The number of fresh 

 water species is small, compared with that of marine types ; and we find terres- 

 trial species in only one of these classes. In former periods also mollusca were 

 chiefly marine ; fluviatile and terrestrial types occurring only in more recent 

 periods." p. 195. The number of " marine species of fishes is far greater than 

 of the fresh water kinds. Among reptiles there are many which are aquatic, 

 either throughout life, or through the earlier period of their existence. But as if 

 animal life rose to higher organization as it leaves the ocean to inhabit dry land 

 or fresh waters, we find that the greater number of the aquatic reptiles are fiu- 

 vialile and but a few marine." The four great types, Radiata, Mollusca, Articu- 

 lataand Vertebrata were introduced at the beginning simultaneously. However, 

 the earliest representatives of all these great types were aquatic. We find in 

 the lowest beds which contain fossils, polypi, together with star fishes, bivalve 

 shells, univalve chambered shells, cases of worms and Crustacea, b?ing at least 

 representatives of seven of nine classes of invertebrate animals, if we are not al- 

 lowed to suppose that medusas existed also, and if insects were still wanting for 

 a time. But in addition to these, fishes among vertebrata are introduced, but 

 fishes only, all of which are exclusively marine. At a somewhat later period 

 insects come in. We find next reptiles in addition to fishes, the lower classes or 

 invertebrates, continuing to be represented through all subsequent epochs, but by 

 species changing gradually at each period, as all classes do after they have been 

 once introduced. The first representatives among reptiles are marine, next huge 

 terrestrial ones, some perhaps flying types, and with them, and perhaps even 

 before, the birds, allied to the wading tribes. Still later mammalia, beginning 

 again with marine and huge terrestrial types, followed by the higher quadru- 

 peds. And lastly, man, at the head of the creation in time as well as in emi- 

 nence, by structure, intelligence, and moral endowments." Geographical Dis- 

 tribution of Animals, p. 197. 



For reliable plates illustrating genera and species of reptiles, vide among 

 other works, 



Cuvier, Regne Animal. 4to edit. Paris. 



Griffith's Animal Kingdom. Reptilia. London, 1832. 



Dumeril et Bibron. Herpetologie generale, ou Histoire Naturelle complete 

 des Reptiles. Paris, 1834. 



Holbrook, North American Herpetology. 5 vols. 4to. Philad., 1842. 



Bonaparte, Iconographia Fauna Italica, Roma. 1832 41. 



Illustrations of Zoology of Southern Africa, by Andrew Smith, M.D. Rep- 

 tilia. London, 1849. 



Voyage dans la Russie Meridionale et la Crimee, execute sous la direction de 

 M. Anatole de Demidoff. (Fauna Pontica.) Paris, 1842. 



Voyage dans l'Amerique Meridionale, par Alcide D'Orbigny. Reptiles. Paris, 

 1847. 



De La Sagra, Histoire Naturelle de Pile de Cuba. Fol. Paris. 



Atlas zu der Reise im Nordlichen Africa, par Edward Ru'ppell. Frankfort am 

 Main, 1826. 



Neue wirbelthiere zu der Fauna von Abyssinien gehorig entdeckt und bes- 

 chrieben von Dr. Edward Riippell. Frankfurt am Main. 1835 40. 



Fauna Caspio-Caucasia, nonnullis observationibus novis, illustravit Edouardus 

 Eichwald. Petropoli, 1841. 



Untersuchungen uber die Fauna Peruana von J. J. M. Tschudi. St. Gallen. 

 184446. 



