I'HK FLORISSANT I.AKK I'.ASIN. 21 



Our examination of the deposits of this lacustrine basin was principally 

 muclt' in a small hill, from which perhaps the largest number of fossils have 

 been taken, lying just south of the house of Mr. Adam Hill, now owned 

 by Mr. Thompson, and upon his ranch. Like the other ancient islets of this 

 upland lake, it now forms a mesa or flat-topped hill about ten or a dozen 

 meter> hi--l i. perhaps a hundred meters long and twenty-five broad. Around 

 its eastern hast- are some of the famous petrified trees huge, upright trunks, 

 standing as rhev grew, which are reported to have been live or six meters 

 high at the advent of the present residents of the region. Piecemeal they 

 have been destroyed liv vandal tourists, until now not one of them rises 

 more than a meter above the surface of the ground, and many of them are 

 entirely leveled; but their huge size is attested by the relics, the largest of 

 which can be seen to have been three or four meters in diameter. These 

 gigantic trees appear to lie Sequoias, as far as can be told from thin sections 

 of the wood submitted to Dr. George L. Gooclale. As is well known, re- 

 mains of more than one species of Sequoia have been found in the shales 



at their base. 







At the opposite sloping end of this me>a u trench -was dug from top t<> 

 bottom to determine the character of the different layers, and the section 

 exposed was carefully measured and studied. In the work of digging this 

 trench we received the very ready and welcome assistance of our com- 

 panion, Mr. F. 0. Bowditch, and of Mr. Hill. 



horn what information we could gain about the wells in this neigh- 

 borhood and from a shaft sunk obliquely in the side of a hill near the 

 northwestern extremity, it would appear that the present bed of the ancient 

 Florissant lake is entire! v similar in composition for at least ten meters below 

 the Mirface, consisting of heavily bedded non-fossiliferous shales, having a 

 conchoidal fracture. Above these basal deposits, on the slope of the hill, 

 we found the following series, from above downward, commencing with the 

 evenly bedded strata : 



SECTION IN SOUTHERN LAKE. 



(By S. H. Scudder and A. Lake*.) 



Centimeters. 

 1. Finely laminated, evenly bedded, light-gray shale ; plants and insects scarce and poorly 



preserved 3.2 



'3. Light-brown, soft and pliable, fine-grained sandstone; unfossiliferous 5 



3. Coarser, ferruginous sandstone; uufossiliferous 



4. Resembling No. 1 ; leaves and insect remains 21 



5. Hard, compact, grayish-black shale, breaking with a conchoidal fracture, seamed in the 



middle with a narrow strip of drab shale ; fragments of plants ~& 



