8 BOTANICAL GAZETTE [SEPTEMBER 
from the southwest, this dune strip has been protected by the 
morainic ridge (fig. 2) north of Point Betsie, and the dunes are 
relatively low and do not have the scenic features to be found in 
similar areas elsewhere. South of the narrow belt of moving dunes 
are found the sand ridges, roughly parallel with the shore, with inter- 
vening depressions, some still containing small ponds. These ponds 
occur almost exclusively in the portion of the region west of Platte 
THe PLATTE PLAINS 
SAND RipGe REGION 
Benzie County 
MiIcHIGAN 
MORAINES 
Decipuous Forest 727 
SAND HILLS DOO 
2 cTamarack Cepar/=,= = 232 = 
XTENSIONS *77~7 42 FoREST GRASS M EADOW aD 
Fic. 1.—Map of Platte Plains sand ridge region 
a 
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ae 
River, probably because of the protection of the morainic ridge 
which has prevented them from being filled by blown sand. Be- 
tween the sand ridges lies a wide trough of relatively slight depth, 
which contains a series of six lakes, more or less completely con- 
nected and draining into the Platte River, and three small lakes 
draining to the north through Otter Creek. 
GroLocy.—This region is regarded as having been a shallow 
embayment of Lake Algonquin, whose shores were formed by 
