403 



I6tb. If a valley occurs, of great or small extent, 

 surrounded by hills or mountains, is there reason to 

 believe that it was ever a lake ? If so, what are the 

 reasons ? 



47th. If it is supposed that in such a situation, a 

 lake ever existed, what are the most probable means by 

 which it was filled up ? 



18th. Is there one, or more, natural openings through 

 the surrounding hills or mountains, at a small elevation 

 above the present level of the valley ? If so, of what 

 description are those openings, and in what direction 

 in relation to such valley ? 



19th. If there are no openings of the above descrip- 

 tion, are there any appearances of a disruption of the 

 hills or mountains, that surround such valley ? If so, 

 what are the appearances, and' on which side, or sides 

 of the valley are they ? 



20th. If there are appearances of a disruption of the 

 hills &c. by water, (which must be supposed, if the 

 lake was filled up with alluvion.) what is the most pro- 

 bable cause of its having been put in operation ? 



21st. Are there any appearances of a neighbouring 

 valley, which may have, likewise, been a lake, and at 

 a higher elevation than the first ? If so, what are the 

 appearances ? 



22d. In this valley, where a lake is supposed to 

 have existed, are there any detached masses of rocks, 

 either rounded or angular, buried in the earth, mixed 

 with the soil, or distributed over the surface of the 

 ground ? If so, of what description are they, and in 



