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LVIII. A Binary Arrangement of the Class Amphibia. Bij 

 A. H. Hawouth, Esq., FeUoiv of the Linmean aiid Horti- 

 cultwal Societies of London, and of the Imperial Natural 

 History Society of Moscoia, S^c. Sfc. 



To the Editor of the Philosophical Magazine and Journal. 

 Sir, 



IN order that some other class of Natural History might be 

 subjected to the test of my binary method of arrangement 

 besides that of Cnistacea, I send you hereunder, a table, so dis- 

 posing of all the numerous genera of the Class Amphibia, or 

 Reptiles ; as far at least as they are published in the elaborate 

 work of Merrem, on that class, in 1820; and who is at once 

 the best and last author on this subject. And to those I have 

 added the three most extraordinary and colossal fossil genera 

 Ichthyosaurus, Plesiosaurus, and Megalosaurus, which have 

 latterly so extensively interested both the geological and zo- 

 ological world. 



In my last communication I noticed to you the manner in 

 which the analogies and affinities of Natural History are in- 

 dicated in my tables, and how these insensibly blend into 

 each other. And I may now further observe, that every 

 dichotomy of the tables, if viewed and taken with the root (or 

 semi-dichotomy) from which it immediately proceeds, may be 

 considered as a sort of triangular circle returning affinitatively 

 into itself: and that the two further dichotomies issuing from 

 each of its branches may be also considered as forming with it 

 a still larger and broader-based triangular or pyramidal circle 

 (inclosing the former) : and so, onwards, until we arrive at the 

 Genera; and including finally (circle within circle) every 

 group in the table of Nature ; together with all the variouf 

 genera into which each group is capable of being divided ; an.. 

 into which each respectively extends, and ends: the great 

 whole composing the vast homogeneo-heterogeneous circle of 

 Nature — " Ubique varians semper tamen eadem." 

 I remain, sir, yours, &c. 



Queen's Elm, Chelsea, Apiil 22, 1825. A. H. Haworth. 



P. S. The generic names are ever in italics in the tables, to 

 distinguish them to the current reader promptly from all others; 

 showing at the same time their due locations, as they occur 

 in the continuous way of a straight line. 



AM PHI- 



