MIGRATIONS. 121 



night, through the grass in search of water, when 

 so circumstanced. Dr. Hancock, in the Zoolo- 

 gical Journal, gives an account of a species of 

 fish, called, by the Indians, the Flat-head Hassar, 

 and belonging to a genus 1 of the family of the 

 Siluridans, which is instructed by its Creator, 

 when the pools, in which they commonly reside, 

 in very dry seasons, lose their water, to take the 

 resolution of marching by land in search of 

 others in which the water is not evaporated. 

 These fish grow to about the length of a foot, 

 and travel in large droves with this view ; they 

 move by night, and their motion is said to be 

 like that of the two-footed lizard. 2 A strong 

 serrated arm constitutes the first ray of its pec- 

 toral fin. 3 Using this as a kind of foot, it should 

 seem, they push themselves forwards, by means 

 of their elastic tail, moving nearly as fast as a 

 man will leisurely walk. The strong plates 

 which envelope their body, probably, facilitate 

 their progress, in the same manner as those 

 under the body of serpents, which in some de- 

 gree perform the office of feet. It is affirmed 

 by the Indians, that they are furnished with an 

 internal supply of water sufficient for their 



1 Doras. 2 Bipes. 



3 PLATE XII. FIG. 1. is a species of Callicthys, a fish of the 

 same habits with the Doras. FIG. 2. is the pectoral ray of ano- 

 ther Siluridan, which was dug up in a village near Barham, but 

 which is not a fossil bone. 



