MM'AUTIKS WHERE TERTIARY INSECTS IIAYK I5EEN FOI'ND IN AMERICA. 



f, < >. The Tertiary lake Kasin at Florissant, 1 already 



t'ainoiis tor its prolific beds of plants and insects, is situated in a narrow 

 valley lii^-li up in the. mountains at the southern extremity of the Front 

 kanv,e n!' <',>!.. railn, at im LiTeat distance from i'ike's I'eak. 



The ba>in U -diowii on Sheet 1;! of the ideological atlas of Colorado, 

 published b\ I >r. Eayden's survey, and its outlines are marked with con- 

 sideralile accuracy, although upon a comparatively small scale. The 

 ancient lake lies in the valley of the present South Fork of Twin ('reek, 

 and of the upper half of the main stream of the same after the South Fork 

 has joined it. Following the old stage road from South Park to Colorado 

 Springs and leaving it just above the railwix station at Florissant, and 

 then taking the road which leads over the divide toward ('anon City, \ve 

 between ill" I'latte Kiver and the Arkansas divide, through the entire 

 length of the basin.- This road crosses tip- South I'latte a short distance. 

 sav a kilom ; r ml a lull', below the month of Twin < Jreek, climbs a IOIILT 

 gradual slope on th" east bank of the river to an open grassy idade about 

 _',.") i ID meters above the sea, and then descends a little more than three kilo- 

 meters from the river to join the valley of Twin ('reek. OIK? scarcely 

 begins the descent Ins attention is attracted by the outcropping of 



drab-colored sha!e>, which continue until almost the very summit of the 

 divide is readied ami the descent toward the Arkansas be^un, a traveling 

 distance ot' not far from 1.'! kilometers. The shales may indeed be seen for 

 several kilometers on the farther side of this divide, but no organic remain> 

 have \ et been found in them. 



IJy climl)iui; a neighboring peak, thrice bapti/ced as ( 'rvstal Mountain, 

 Tojiax Hutte, and Cheops Pyramid, and known to the old miners as Slim 

 Jim, we obtained an admirable bird's-eye view of the ancient lake and the 



'This uccouut of FlurUsant, is takou aliimst limlily from a paprr by Prof. Arthur Lakes ami 

 myself (Hul I - < .ml. Surv. Ton., vol. fi, 1881, pp. 279, seq.). 



17 

 VOL XIII - ^ 



