GEOLOGY OF LA SALLK COUNTY. 



57 



Alethopteris, Asterophyllites, Cordaites, Botryconus, 

 Calamites, Annularia, Lepidodendra, Sig-illaria. 



The localities for Lepidodendra and Sig-illaria are 

 very numerous — west of Ivowell; ravines in northeast 

 part of Deer Park Township; Marseilles in Streator 

 sandstone, about four miles west of Marseilles, on 

 south side of Illinois river, furnish gfood specimens. 

 Most of the ravines in Deer Park Township furnish 

 trunks of trees and hug-e. anomalous petrifactions 

 which deserve more attention than they have yet 

 received. See plate II., Fiofs. 14, 15, 16. Theorig-inal of 

 17 is more than 10 in. in least diameter. Nearly south 

 of Hon. Urbin Ellsworth's residence in Deer Park 

 Township, a fourth of a mile from the Big- Vermillion, 

 we saw^ a trunk, represented in Fig*. 14, over thirty 

 feet in leng-th and twelve inches in diameter, and 

 the appearance as it lay. the north side covered by 

 black slate, sug-gested the idea that it sent off a branch 

 at each curve; ab., Fig-. 15, is a section at rig-ht ang-les 

 to a. Fig-. 14, 1,1, being the enclosing- slates. Another 

 specimen in a ravine on the land of Mr. Henry Dim- 

 mick is sixteen feet long-, about a foot in diameter, 

 comes to a point at the south end, but for twelve feet 

 is about uniform in thickness, except a nearly spherical 

 enlarg-ement about three feet from w^here the north end 

 runs into the bluff as shown in Fig*. 16. 



A remarkable locality for fossil ferns exists on 

 Covell creek, about sixty rods east of the C, B. & Q. 

 bridg-e. Here in the clay shales at about the water's 

 level is a layer about a foot thick, containing- many 

 species of ferns, cordaites, lepidodendra, fossil fruits 

 and many other thing-s. There seems to be three fos- 

 sil bearing- beds in the bluffs bordering- this creek, but 

 w^e have explored but one of them, and that only par- 

 tially. We believe that these beds will prove almost. 



