24 SAND DUNE REGION OF SAGINAW BAY. 



These temporary ponds maj' or may not l^e filled with grasses and sedges. 

 In the former case, upon drying up in the summer, small grassy areas 

 are left, and in the latter expanses of drying mud. These ponds mostly 

 harbor forms (a) that have aquatic larval stages that are passed before 

 the ponds vanish (e. g.. frogs, tree frogs and salamanders), or (b) that 

 may aestivate (a number of gasteropods), but some truly aquatic forms 

 annually get into them that either migrate or are killed by the dning-up. 

 For example, turtles and water snakes are occasionally found in these 

 and the bugs Xotonectidae and Belostoma were found dying in the 

 beds of dried-up ponds in July. The beds of the transient ponds that 

 are not filled with grasses and sedges furnish feeding grounds for several 

 sandpipers and plovers — the greater yellow-legs, least sandpiper, and 

 semipalmated plover were observed. 



Permanent Ponds: There are also many bodies of water in the sand 

 region that do not usually drA^ up in the summer. Those studied in 

 detail are, Orr Lake, Mud Pond, and Long Lake, all on Sand Point. 

 .The two former are deep ponds, with a bottom of mud and peat and a 

 rich aquatic vegetation. The animals collected in them were such pond 

 forms as Planorhis cainpanulatus, P. exacuous and Segmentina crass- 

 ilahris, and Rana clamitans. Another small one investigated had the 

 following fish: bullhead, tad-pole stone cat and mud minnow. 



Long Lake is a long narrow lake l^ack (south) of the first dune at the 

 end and north side of Sand Point. It is very shallow, nowhere attain- 

 ing a depth of over two or three feet. The bottom is sand, and there 

 is not an abundant flora except at the east end where the bottom is 

 peaty. Much of the bottom is bare, but there is a sparse gro-«i;h of 

 rushes about the shore, a few large patches of a very short chara, and 

 small patches of water-lilies. At the ends there is a slight deposit 

 of peaty material, and there the aquatic vegetation is much better 

 developed. (Plates XII, XIII a.) 



There are no fish in the lake. The reptiles and amphibians are 

 represented by the painted turtle, Blanding turtle, and the red nevrt, 

 and such marginal forms as the water snake and green frog. ]\Iany 

 tadpoles of the latter are found in the lake, and there is an abundance 

 of such invertebrates as Xotonectidae, dragon-fly larvae, etc. The 

 shells found here are listed by Baker. 



On the south end of Stony Island there are three ponds (Plate "\'III b) 

 that have apparently been formed much as the lagoon ponds in the 

 sand region, and the fauna is about the same. The painted turtle. 

 Blanding tm'tle, red newt, dragon-fly larvae and numerous shells were 

 collected. 



Rush Lake, by far the largest body of water in this region, is outside 

 of the sand region proper. It is a part of the series of swamps that 



