156 Prof. E. D. Cope on the Systematic Relations of Fishes. 



Lopliobranchiate divisions, wliicli are obvionslynot related to it. 

 These, with the Malacopterygians and Acantliopterygians, he 

 erected into a sixth subclass, the Teleostei. This subclass, 

 containing the greater part of existing fishes, embraced six 

 orders, viz. : — Acanthopteri (Cuvier's Acanthopterygians) , 

 Anacanthini (new, for the cod family &c) , Pharyngognathi 

 (new, for fishes with connate inferior pharyngeal bones), 

 Physostomi (Malacopterygians of Cuvier, nearly) • Plecto- 

 gnathi and Lophobranchii of Cuvier. The great number of 

 facts in the anatomy of fishes added by Miiller constitute him 

 the father of modern ichthyology. 



Professor Gill, in 1861, adopted many of the divisions of 

 Miiller, and rejected some ; others were newly proposed. But 

 four subclasses were recognized : — the Dermopteri, which in- 

 cludes also Miiller's Leptocardii ; the Elasmobrancliii, equi- 

 valent to Miiller's Selachii ; the Ganoidci, including here 

 Miiller's Dipnoi ; and the Teleostei. Six orders were attri- 

 buted to the last subclass, which were quite different from 

 those of Miiller. 



Subsequent to this publication, important contributions to 

 the system have been made by Kner, Liitken, Gill, Huxley, 

 &c., which will be noticed at the proper time. 



The writer, liaving been engaged in an examination of the 

 osteology of the bony fishes, and general anatomical studies 

 of the whole, has proposed to point out some further modifica- 

 tions of the received system, wliich he believes will render it 

 a closer reflection of nature. There are some portions of the 

 skeleton which have been to a great extent overlooked in 

 seeking for indications of likeness and difference of types; and 

 the estimation in which many known characters are held may 

 be much altered on the study of extended material. The 

 skeletons on which the present study is made are one thousand 

 in number — two hundred belonging to the Academy of Natural 

 Sciences of Philadelphia, and eight hundi'ed to the writer, 

 being the collection made by Professor Joseph Hyrtl, the 

 distinguished anatomist of Vienna. This collection has long 

 been known to anatomists in Europe as the most beautifully 

 and reliably prepared in existence, and as valuable as any for 

 study, on account of the fulness of the representation of the 

 various types. 



II. Special on the Ganoids. 



Recurring to Miiller's system, the writer adopts, as charac- 

 terized beyond dispute, his subclasses or orders of Leptocardii, 

 Dermopteri, Selachii, and Dipnoi, and confines himself at 



