MICHIGAN ACADEMY OF SCIENCE. 



37 



KEY TO MAPS AND CHARTS. 



Chart. I. Classification of Lakes of Temperate Regions. 



Chart II. Comparison of Beach Pools of Douglas Lake. 



Chart III. Comparison of Pools of Different Regions. 



Chart IV. Comparison of Temporary Swamps of Different Regions. 



ABREVIATIONS USED IN CHARTS. 



A abundant. 



b breeding, only. 



C common. 



d dead. 



F frequent. 



I infrequent. 



j juvenile. 



1 local. 



q quite. 



R rare. 



V very. 



y young. 



The numbers refer to the numbers of 

 the habitats given in former pa- 

 pers (5, 7). 



Map 1. Map of the Northern End of the Southern Peninsula of Michigan, 

 showing Beaches of Glacial Lakes Algonquin and Nipissing.'^ 



The cross-hatched portions show what was land during the time of the 

 Algonquin highest beach level; the highest Nipissing beach is represented 

 by the line just inside the present lake shore and surrounding Mullet, Burt 

 and Crooked Lakes. The figures in the different lakes are their approxi- 

 mate heights above sea-level. The large squares represent the townships, 

 or areas six miles square. (Reproduced from 6). 



Map 2. Douglas Lake. 



a barrier beach pools. 



b Pine Point. 



c Hook Point. 



d Swamp Point. 



e Sedge Point. 



f South Point. 



g Stony Point. 



h North Fish Tail Bay. 



j South Fish Tail Bay. 



k Grapevine Point. 



1 head of Carp Creek. 



m Maple River. 



n Bessey Creek. 



o outer edge of triangular bar. 



Maps 3, 4, ^ cind 6. Barrier Beach Formation. 



Four successive maps made of the same region in the summer of 1912, 

 surveyed on July 22, July 30, August 16, and September 5, respectively. 

 All four maps made on the scale; the oblong area inside of the two cross-lines 

 in maps 5 and 6 represent the entire area of maps 3 and 4. (Size 25 by 30 m.) 

 Cross-hatched areas represent land. Contour interval, showing depths of 

 water, 5 cm. st and dotted lines represent stony-bottomed areas; r, a rock; 

 the remainder of the bottom was sandy. Numbers represent depths in cm. 



Map 7. Pine Point Lagoon; made July 29, 1912. 



Contour interval, showing depths of water, 5 cm. Squares, shown only on 

 land, 5 m. each way. This map shows the lagoon just after it was formed; 

 in 1913 the spit was one-third longer and more completely surrounded the 

 pond. 



Map. 8. Hook Point: made August 20, 1912. 



Contour interval, showing depths of water, 20 cm., out to 1 m. in depth, 



'The data for this map were taken from the laree map accompanying (11), from (12), and from cor- 

 rections kindly made by Mr. Leverett from his field notes. 



