124 



the more elongated shape of the body, are retained in the adults, and 

 unless complete series can be examined to show the gradation of these 

 changes from the young to the adult, distinct species could easily be 

 supposed to exist by examining merely the extremes of the series. 

 An error of this sort has led to the establishment of species, which 

 Girard supposed to be closely allied to E. Jacksoni and to E. lateralis^ 

 but which are founded merely on some characters of the young, more 

 prominent than usual in the adult or middle-sized specimens. 



The only specimen of Girard's Emhiotoca argyrosoma preserved in 

 the Smithsonian Institution is in such a poor condition that it is im- 

 possible to say certainly whether it is a true Emhiotoca or not. But 

 from what remains of it, it would seem to be a genus by itself, as it 

 difiers entirely from any other species of this family by its large 

 scales, the rounded head, and the elongated shape of the body. 



Authorities. 



Agassiz (i.) Extraordinary fishes from California, constituting a 



new family. Am. Jour. xvi. Nov. 1853, p. 380-390. 

 Agassiz (L.) Additional notes on the Holconoti, Am. Jour. xvii. 



May, 1854, pp. 365-369. 

 Gibbons ( W. P.) Proceedings of the California Academy of Natural 



Science in Daily Placer Times and Transcript, San Francisco, 



Cal., issue of May 18, 1854, May 30, 1854, and June 21, 1854. 

 Gibbons ( W. P.) Descriptions of four new species of Viviparous 



fishes from Sacramento River and the Bay of San Francisco. 



Read before the Cal. Acad. N. S., May 15, 1854. Proc. Phil. 



Acad. N. S. VII., July 1854, pp. 105-106. 

 Gibbons {W. P.) Descriptions of new species of Viviparous, 



marine, and fresh-water fishes, from the Bay of San Francisco, 



and from the river and lagoons of the Sacramento. Read 



before the Cal. Acad, of N. S., Jan. 9, May 15, 22, 29, 1854. 



Proc. Phil. Acad. N. S. vii., July 1854, pp. 122-126. 

 Girard {Charles). Descriptions of new fishes, collected by Dr. A. 



L. Heermann, naturalist, attached to the Survey of the Pacific 



Rail Road Route, under Lieut. R. S. Williamson, U. S. A. 



Proc. Phil. Acad. N. S. vii., August, 1854, pp. 134-135. 

 Girard (Charles). Enumeration of the marine fishes, collected at 



San Francisco, Cal., by Dr. C. B. R. Kennerly, naturalist 



attached to the Survey of the Pacific R. R. Route, under Lieut. 



A. W. Whipple. Proc. Phil. Acad. N. S. vii., August 1854, 



p. 141. 

 Girard {(Charles). Observations upon a collection of fishes, made 



upon the Pacific coast of the United States, by Lieut. W. P. 



Trowbridge, U. S. A., for the Musemn of the Smithsonian In- 



