SAND DUNE REGION OF SAGINAW BAY. 31 



long-billed marsh wren, rose-breasted grosl)eak, catl)ird, woodchuck, 

 bluebird, chewink. red-headed woodpecker, fox snake, red-bellied 

 snake, common garter-snake, brown snake, red squirrel, and chip- 

 munk. 



3. Northern forms that in Michigan extend considerably south of 

 this latitude, e. g., sora rail, Virginia rail, swamp sparrow, swamp 

 fly honeysuckle, tamarack, pitcher plant, cassandra, Labrador tea, 

 Caml^ridge frog, arbor vitae, yellow birch, chestnut-sided warbler, 

 Wilson thrush, chickadee, porcupine. 



4. Southern forms that in Michigan are known to extend little if 

 any north of this latitude, e. g., Carolina wren, - Butler's garter- 

 snake, - wood reed grass, ■ butternut, ^ black walnut. - shag-bark 

 hickory, - Carya microcarpn . ^ yellow-barked oak, - scarlet oak. ^ spice 

 bush, } American crab, ^sassafras, ' hog-nosed snake, 'blue-tailed skink ', 

 ribbon snake. ^ ' ^ 



5. Northern forms that in Michigan are known to breed little if any 

 south of this latitude, e.g., American hare, ■ ' ^ blackburnian warbler, ^ " ' 

 black-throated green warbler, * American yew, ^ balsam fir, - hemlock, ^ 

 black spruce, ^ ' * Norway pine, - Clintonia horealis, * swamp red currant, * 

 sessile-leaved twisted stock, * false miterwort. * Polypodium vulgare, ^ 

 Phegopteris polypodiales, ^ Woodsia obtusa, ' Lyco'podium cotnplana- 

 tum, ^ jack pine, ' common hair grass, ' Agropyron dasystachum, ' 

 Cyperus houghtoni, ^ Ceanothus ovatus, Amelanchier spicata, ^ Salix glau- 

 cophylla, ^ Hahenana hookeri, ' sweet fern, ' Hieracium umbellatum, ' 

 Linaria canadensis. ' 



I believe that we may safely conclude that the environic conditions 

 along this coast of Michigan while permitting a few southern forms 

 are not favorable to the intrusion of a large number. On the other 

 hand, it seems as if they do permit a more northern extension of range 

 on the part of a few of the forms that find their northern limit in 

 the interior of the state farther to the southward. However, more 

 data on the fauna and flora of the interior of the state must be 

 obtained before the extent of the influence of the variations in climate 

 upon the distribution of the forms can be ascertained. 



LITERATURE. 



The literature on this region is meager. There are a number of 

 references to the geology (see Lane, 1900. p. 2 et seq.), but the only 

 observations that I have been able to find on the natural historv. 



^Inhabiting sand ridges. 

 ^Inliabiting drained swamps or lov\' ground. 

 ^Inhabiting shaded rock cliffs. 

 ^Inhabiting bogs. 



