Nachdruck verboten. 

 Uebersetzungsrecht vorbehalten. 



On the larval development of Amia calva. 



By 



Bashford Dean, 



Columbia College, New York. 



With Plates 9—11 and 17 figures in text. 



The early developmental history of the Ganoids, Lepidosteus, 

 Äcipenser and Amia, forms an unbroken chain of evidence to connect 

 what are essentially the embryonic characters of the Elasmobranchs 

 with those of the Teleosts. Thus it is known that Lepidosteus ^) is 

 decidedly shark-like in its early developmental features ; and that 

 Amia^ on the other hand ^) is clearly Teleostean ; — a ränge in early 

 ontogeny which can at the least be regarded as providing the most 

 interesting confirmation of the results of palaeontologists ^) as to the 

 phylogeny of the Teleostomes. The Ganoids, in short, have made 

 good their Claims to be regarded as an interraediate group : and from 

 this Staudpoint the further study of their developmental characters 

 might well be expected to demonstrate more defiuitely the relation- 

 ships and the interrelationships of the Ganoids and to point out more 

 clearly the lines of evolution of -many of the puzzling processes in 

 the specialized developmental type of the Teleost. 



The sub-classes of Fishes are broadly separated in the characters 



1) Dean, Early development of Gar-pike and Sturgeon, in : J. 

 Morph., 1895, V. 11, No. 1, p. 1—62, tab. 1—4. 



2) Dean, Early development of Amia, 1896, in: Quart. J. Micr. Sc, 

 V. 38, p. 413—444, tab. 30—32. 



3) Cf. Esp. Tkaquaik, The Palaeoniscidae, in: Mem. Pal. Soc, 1876, 

 and Smith Woodwakd, On the palaeontology of Sturgeons, in : P. Geol. 

 Ass., 1889, V. 11, Nos. 1 and 2. 



