36 Indian Mounds and Shdls in Michigan. 



while in the Detroit mound skull this space measures only three quar- 

 ters of an inch ; and in this respect it presents about the same condi- • 

 tions as the skull of a chimpanzee. As the two other crania from the 

 same mound offered no such peculiarities, the skull which has just 

 been described must be considered simply as an extrenae case of indi- 

 vidual variation from the ordinary form. There are no signs of arti- 

 ficial deformity. 



The single tibia accompanying this collection is somewhat flattened. 

 Mr. Gilman, under an appropriation made by the trustees, has ex- 

 plored a series of mounds at the head of St. Clair river, and the col- 

 lections made by him have been received, and were accompanied with 

 the following report : 



The mounds situated at the head of the St. Clair river extend from 

 south of Fort Gratiot for one and one half miles northward", along the 

 west shore of the river and of Lake Huron. It is altogether probable 

 that they reach much farther, both northward and southward ; but I 

 have traced, examined, and liilly identified them for the distance men- 

 tioned. Similar works have been found on the opposite side of the 

 river, in Canada. Isolated mounds in the interior also exist, an inter- 

 esting example of which is seen on the west shore of the Black river 

 (a tributary of the St. Clair), at a point about one and three quarter 

 miles southwest of Gratiot ; the mound referred to having been exposed, 

 some years ago, by the grading of a road through it, resulted in the 

 loss of a large amount of valuable relics. 



With few exceptions, all these mounds have a general resemblance, 

 and bear the appearance of terrace-like embankments, from ten to 

 twenty and twenty-five feet in height ; they are much longer than 

 wide, and run nearly parallel to the general direction of the river and 

 lake shore, which here does not vary much from north and south. 

 They are mostly of the Drift formation, subsequently modified or added 

 to by man for the various objects for which they were occupied, 

 whether for the purposes of interment, habitation, or the manufiicture 

 of the rude implements connected with the daily life of that period ; 

 and, from the topographical features and the geographical position, 

 they must have formed favorite places of retreat in war time. 



Mound No. 1 is composed chiefly of sand and gravel, is about t^vo 

 hundred feet long by fifty feet wide, and is fifteen feet above the level 

 of the river. It has rather abruptly curving sides, and is built on a 

 slope of the ridge, of Drift formation, on which the village of Gratiot 

 stands. 



A large excavation, made about fifty feet from the south end of the 

 mound, disclosed the remains of four human bodies, at a depth of four 



