Oll tlio liirval development of Aiuia calva. 641 



I. Habits of larvae, pag. 642. 



IL Description of typical stages from that of the second day be- 

 fore hatcbing to tbat of tbe end of tbe fiftb week, pag. 644. 



III. Notes ou orgauogeny, pag. 654. 



IV. CoDclusions. Comparison of larval cbaracters of tbis form 



with tbose of otber Ganoids, and Teleosts (Siluroids 



especially), pag. 669. 

 A list of tbe literature on tbe embryology of the Ganoids has 

 been given in tbe Journal of Morpbology, V. 11 (1895), p. 54 — 55. 

 To tbis is to be added tbe followina: titles : 



ViRCHOw, H., On the breeding habits and gill vessels of Lepidosteus, 



in: SB. Akad. Wiss. Berlin, 19. Jan. 1894, p. 33—44. 

 Furchungsbilder von Amia calva, in: SB. Ges. Nat. Fr. Berlin, 1896, 



No. 3, p. 41—42. 

 NiCKERSOK^, W. S., The development of the scales of Lepidosteus, in : 



Bull. Mus. Comp. Zool., Harvard 1893, V. 24, No. 5, p. 114—144. 

 JuxGEESBN, H. P. E., Die Embrj^onalniere von Amia calva, in : Zool. 



Anz. 1894, No. 451. 

 Dean, Basheoed, Spawning habits and early development of Amia, in : 



Quart. J. Micr. Sc, 1895, V. 13, p. 413—444. 



In Ämia, as in fishes generally, tbe distinctly larval period may 

 be Said to be initiated by the process of hatcbing and to be con- 

 tinued to the period of the ripening of the sexual products; usually, 

 however, this period is looked upon as referring to the earliest weeks 

 of the free-swimming existence of the fish, — since it is within this 

 Short time that nearly every growth process takes place. Thus in 

 the case of Amia larvae of the fifth week, although as yet scarcely 

 an inch in length, have attained practically their adult conditions, in- 

 cluding the essential fin cbaracters, scales and teeth. And it is to 

 this point that the present outline has been carried: the further 

 changes, those mainly of the genito-urinary system, body and fin pro- 

 portions, coloration, have been practically omitted from the present 

 discussion. 



Tbe later development of Amia was hitherto known from the 

 classic memoir of E. P. Allis on the lateral line system, in : J. Morph., 

 1889, in which many larval stages were figured but not considered 

 apart from the theme of the paper. The only additional account of 

 Amia's later development is the discussion by H. F. E. Jungeksen 

 of the larval excretory system, referred to above. 



Zool. Jahrb. IX. Abth. f. Syst. 42 



