ZOOLOGY. 333 



extreme in excessive diflt'ereiitiatiou. Dr. Giiutlicr lias published an 

 " lutrodnction to the Study of Fislies," in which he recognizes as orders 

 certain artificial groups of Teleosts current for a loug time; that is, 

 the Acanthopterygii, Acanthopterygii Pharyngognathi, Anacanthini^ 

 Physostoini. »S:c. 



The characters used to differentiate these "orders" fail in certain 

 representati\es referred to each group, and are of really little more 

 systematic imi)ortance in several cases than those used to distinguish 

 the "orders" of Birds. Nevertheless, to each of the "orders" in 

 question are assigned forms ^vhich do really differ in important ana- 

 tomical details, and which have far less relation to the types with which 

 they are confounded than do the types of the so-called orders exhibit 

 among themselves. We have, consequently, evils here, not only of undue 

 valuation, but also radical defects in appreciation of relationships. 

 But the same author applies a standard as different as possible to the 

 classilication of the generalized types of Fishes 5 committiug, at the 

 same time, the great mistake of calling those generalized types the 

 highest. All the typical Ganoids, as well as the Polypteroids, and 

 Dipnoans are confused together in one heterogeneous order; all the 

 Chimairoids, and all the Sharks and Bays, are thrown together in a 

 second. There can be no question but that representatives of each of 

 these last two so-called " orders" exhibit far greater diversities in their 

 structure, inter se, than do any of the orders of existing mammals. 

 It is difficult to believe that any consideration could have been given to 

 the principles of taxonomy, or that thought could have been actively 

 involved in such schemes as the last one noticed. 



As to the new orders recently proposed, and to be noticed hereafter, it 

 is probable that the value of the several groups endowed with such rank 

 will be questioned by the majority of naturalists, and that the types so 

 distinguished will ultimately be degraded in rank. 



The language of the original from which the abstract is compiled is 

 followed as closely as the case will permit, as the advantages of such a 

 course must be obvious to all on a little reflection. It has however 

 been generally found to be necessary to limit the abstract to the illus- 

 tration of the prominent idea underlying the original memoir, arid pass 

 by the proofs and collateral arguments. At the same time it has been 

 often attempted to bring the new discovery into relation with the i»re- 

 vious status of information respecting the group under consideration. 

 As to the special discoveries recorded, they have been generally selected 

 (1) on account of the modifications the forms considered force on the 

 system; or (2) for the reason that they are or have been deemed to be 

 of high taxonomic importance; or (3) because the animals j^er se are of 

 general interest; or, finally (4), because they are of special interest to 

 the American naturalist. Of course, zoologists cultivating limited fields 

 of research will find in omissions cause for censure, and may urge that 

 discoveries of inferior importance have been noticed to the exclusion of 



