840 STRUCTURE AND DEVELOPMENT OF LEPIDOSTEUS. 



very unlike those of Ganoids and approaching the Amphibian 

 type, they form a very well-defined group, and one very dis- 

 tinctly separated from the Ganoids. 



No doubt the Chondrostean Ganoids are nearly as far re- 

 moved from the Teleostei as from the Dipnoi, but the links 

 uniting these Ganoids with the Teleostei have been so fully pre- 

 served in the existing fauna of the globe, that the two groups 

 almost run into each other. If, in fact, we were anxious to make 

 any radical change in the ordinary classification of Fishes, it 

 would be by uniting the Teleostei and Ganoids, or rather con- 

 stituting the Teleostei into one of the sub-groups of the Ganoids, 

 equivalent to the Chondrostei. We do not recommend such an 

 arrangement, which in view of the great preponderance of the 

 Teleostei amongst living Fishes would be highly inconvenient, 

 but the step from Amia to the Teleostei is certainly not so great 

 as that from the Chondrostei to Amia, and is undoubtedly less 

 than that from the Selachii to the Holocephali. 



LIST OF MEMOIRS ON THE ANATOMY AND DEVELOPMENT OF 

 LEPIDOSTEUS. 



1. Agassiz, A. "The Development of Lepidosteus." Part I., Proc. 

 Amer. A cad. Arts and Sciences, Vol. xiv. 1879. 



2. Agassiz, L. Recherches s. I. Poissons Fossiles. Neuchatel. 1833 

 45. 



3. Boas, J. E. " Ueber Herz u. Arterienbogen bei Ceradotus u. Protop- 

 terus," Morphol. Jahrbuch, Vol. VI. 1880. 



4. Davidoff, M. von. " Beitrage z. vergleich. Anat. d. hinteren Glied- 

 massen d. Fische," Morphol. Jahrbuch, Vol. vi. 1880. 



5. Gegenbaur, C. Uutersuch. z. vergleich. Anat. d. Wirbelthiere, 

 Heft II., Schnltergiirtel d. Wirbelthiere. Brustflosse der Fische. Leipzig, 

 1865. 



6. Gegenbaur, C. " Zur Entwick. d. Wirbelsaule d. Lepidosteus, &c." 

 Jenaische Zeitschrift, Vol. ill. 1867. 



7. Hertwig, O. "Ueber d. Hautskelet d. Fische (Lepidosteus u. 

 Polypterus)? Morphol. Jahrbuch, Vol. v. 1879. 



8. Hceven, Van der. " Ueber d. zellige Schwimmblase d. Lepidostens? 

 M tiller's Archiv, 1841. 



