Description of a " White Fish,"' or " White Whaled 603 



alent to other sub-orders, we suggest that these mistaken 

 views are owing to the great variation produced by this 

 synthesis, in connection with the lowness of their type, 

 which besides renders the families when once limited very 

 difficult to arrange in a natural series ? By a parity of 

 reasoning, to return again to the Bombyces, I satisfy my- 

 self that the subdivisions of that group are in fact sub- 

 families. The Hepiali are the lowest sub-family of the 

 Bombyces ; and since the lower genera of most families 

 of insects differ much more among themselves than the 

 highest genera of the same family, I feel convinced that 

 the two groups of genera of which Cossus and Hepialus 

 are types are but sections of the same sub-family. 



EXPLANATION OF THE WOOD-CUTS. 



Fig. 1. Thorax of Gorgopis purpurascens. 9 nat. size. 

 Fig. 2. Thorax of Polystaschotes punctatus, magnified. 

 Figs. 3, 4. Wings of Hepialus lupulinus. 9 

 Figs. 5, 6. Wings of P. punctatus. 



a, costal recurrents. 



6, sub-median recurrents. 



Art. XVI. — Description of a " White Fish" or " White 

 Whale," {Beluga borealis Lesson.) By Jeffries Wy- 

 MAN, M. D., Prof, of Anatomy in Harvard College. 



[Communicated April lutli and May 20tli, 1863.] 



This specimen* was a male, captured in the Gulf of 

 St. Lawrence, and has been on public exhibition in a 

 water tank for nearly two years. He weighed about 700 



* I am indebted to the kindness of Dr. James C. Wliite, Curator of the Society's 

 collection of Comparative Anatomy, for the opportunitj' of dissecting this speci- 

 men. The carcass was presented to the Society by 1'. T. Barnum, Esq., and tlie 

 slieleton is to be placed in the Society's cabinet. In the dissection I was assisted 

 by Mr. Horace Mann, of the Lawrence Scientific School. 



