190 



ESSAY ON CLASSIFICATION, 



Paet I. 



his views of these relations between classes, orders, genera, species, and varieties, 

 by comparisons, in the following manner : — ^ 



His arrangement of the animal kingdom is presented in the following diagram, 

 compiled from the twelfth edition, published in 1766. 



CLASSIFICATION OF LINNAEUS. 



Cl. 1. Mammalia. Ord. Primates, Bruta, Ferse, Glires, Pecora, Bellua>, Cete. 



Cl. 2. A V e s . Ord. Aecipitres, Picae, Anseres, Grallae, Gallinse, Passeres. 



Cl. 3. Amphibia. Ord. Reptiles, Serpentes, Nantes. 



Cl. 4. Pisces, Ord. Apodes, Jugulares, Thoracici, Abdominales. 



Cl. 5. I n s e c t a . Ord. Coleoptera, Hemiptera, Lepidoptera, Neuroptera, Hymenoptera, Diptera, 



Aptera. 



Cl. 6. Vermes. Ord. Intestina, Mollusca, Testacea, Lithophyta, Zoophyta. 



In the earlier editions, up to the tenth, the class of Mammalia was called 

 Quadrupedia, and did not contain the Cetaceans, which were still included among 

 the Fishes. There seems never to have existed any discrepancy among naturalists 

 respecting the natural limits of the class of Birds, since it was first characterized 

 by Linnajus, in a manner which excluded the Bats and referred them to the class 

 of Mammalia. In the early editions of the "Systema Naturae," the class of Reptiles 

 embraces the same animals as in the systems of the most recent investigators; 

 but since the tenth edition, it has been encumbered with the addition of the 

 cartilaginous and semicartilaginous Fishes, a retrograde movement suggested by some 

 inaccurate observations of Dr. Garden. The class of Fishes is very well limited 

 in the early editions of the Systema, with the exception of the admission of the 

 Cetaceans, (Plagiuri,) which were correctly referred to the class of Mammalia, in 

 the tenth edition. In the later editions, however, the Cyclostoms, Plagiostoms, 

 Chimseroa, Sturgeons, Lophioids, Discoboli, Gymnodonts, Scleroderms, and Lopho- 

 branches are excluded from it and referred to the class of Reptiles. The class 

 of Insects,^ as limited by Linnaeus, embraces not only what are now considered as 



* See Systema Naturae, 12th edit,, p. 13, 



'' Aristotle divides this group more correctly than 



Linnajus, as he admits already two classes, (yertj 



Heyiara) among them, the Malacostraca, (Crustacea,) 



and the Entoma, (Insects.) Hist. Anim., Chap. VI. 



He seems also to have understood correctly the 

 natural limits of the classes of Mammalia and Rep- 

 tiles, for he distinguishes the Viviparous and Ovipa- 

 rous Quadrupeds, and nowhere confounds Fishes with 

 Reptiles. Ibid. 



