: iy aeipeactasce re wage one ri es 
Contributions to the Geology of Texas. 25 
Among the latter, the genus Hzogyra, acts a very important 
part in the constitution of .the. fauna, some species of the genus 
having a very wide geographical range, and occurring almost eve- 
rywhere in a great number of individual Is. One. species which 
resembles a Chama in external 
h through “ whole extent of 
Another still more important, fet nupt Ahr considered? in the 
general distribution throughout | end ae oe of the genera 
urites and, Caprina.. The. forn 
in the cretaceous depos sits of New .. 
pearance dey pede rm ofa ie 
me. ge 
ean na see 
7 with, either ind 
z $ * = 
esetwo ge 
miu strata hai 
wperaas tammy os 
important part in the 
id around the “Mediterranean, 
: hin the ecretaceous for- 
mation of. Boul teresting analogy is 
hereby. “establishe ai the. deposits of the» creta~ 
ceous period, and those of the south,of Europe, ‘the more rs 
king,.if, we considervat the same. time, the similarity of mineral- 
constitution. » Between, the continents of America and 
must therefore have. existed at the time of the cre- 
taceous period, such a relation that in. both, the. same modifica- 
tions in. the zoological character distinguished the marine Fauna’ 
a Gale from that. of the .. And thence, we proceed 
fart paint interesting conclusion; that» the same Wa ise: in- 
flection-of the isothermal lines whie ich is at present’so remarkable 
in thei ir course froux they west side: of -the continent of Europe to- 
wards, t side «the continent of America, already existed 
at a — of the. veg gomow? as tha t of she cretaceous 
ALON ee om ox 
Strata.older. than Se. At the time ine T wrote my 
Apel td of; Texas, I had no. knowledge of the 
= : in the,c ut f any strata older than the cretaceous | 
a singlexock of granite about fif- 
* men of this t Phi ade the Museum of the Acad. 
“ "asia Sine nces, whi hs ae [ie tb ss oll county; Alabama, by 
“ae & scout Vol. - No. 16-—Jaly, le 4 
eaet of Pideickeeen But in the early part 
of “agen, a shor ime before my leaving the country, I had a 3 
