with descriptions of new Fossils. 217 
Section taken about one mile south of the preceding at head of Clear 
creek :— 
No. 1. Cretaceous strata in horizontal beds, - - >. 110 
“ 2. Slope, covered with conglomerate, composed of pebbles 
of sandstone and calciferous sand rock, rather firmly cemented, 12 ft. 
“ 3. Potsdam sandstone, consisting of thin layers of variegated 
green, gray and purplish, sandy limestone, with bands of dolo- 
mite and silico-calcareous rock interstratified. Some of the 
beds are highly charged with trilobites, of which the most 
common are Arionellus Texanus, Dikelocephalus Rameri and 
Conocephalites Billingsi, 40 ft. 
“ 4. Highly ferruginous silicious sandstone, composed of fine 
grains, loosely cemented, passing ownwards into, coarse grit- 
stone and conglomerate. The upper beds contain Lingula and ps 
3 (2 is s ss 0 . - 0 
“ 6. Flesh-colored granite, jnterstratified with veins of milky 
quartz, - - - - - - - 6 ft. 
Section near fhiouth of Morgan’s creek :— 
No. 1. Coarse-textured, variegated purple, green and brown lime- 
stone, soft and crumbling readily to sand,  - . . 
“2. Greenish and gray calcareous sandstone made up of fine 
grains, - : : my - 3 . 
“ 3. Slope, with projecting ledges of white, green and gray 
limestone with Conocephalites Billingsi, Agnostus Coloradoen- 
ss and Arionellus, - - = i = ~ 37 
“ 4. Thin beds of calcareo-silicious limestone with same trilo- 
a: fore ES . “. s ae 
bites as No 0 ft. 
“ 5. Brown ferruginous sandstone with Lingula, - - °60 
i S < 110 
“6. Flesh-colored granite, ® : si 
The beet exhibitions of this group of rocks occur in the ee 
) ; th og e 
tical. Thus in the Texan beds we have found Dikelocepha- 
us, Bathyurus, Arionellus, Conocephalites, Agnostus, ps bees 
