Geology and Mineralogy. 12? 
thickness of 1200 feet, the middle of 610, and the w —— 
with P. Jeffersonius of Virginia. This Estrella Tertiary is probably of 
later age than the Santa Barbara. Mr. Conrad adds, “T have no doubt 
that the Atlantic and Pacific oceans were connected in the Eocene pe- 
riod ; and the fossils herein described afford strong evidence that the con- 
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43 
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n Pedro, in 110° 30’ W., which are referred to the Creta- 
ceous, ban no 0 fossils were found to remove all 
The Report is illustrated by sections and roi maps, but the sections 
are om ie ted and seem to be generally a result of very hast 
observa 
13. aie of New Species of Blastoidea a the Paleozoic 
rocks of the Western States, with some observations on the Structure of 
the summit of the Genus Pentremites ; by B. F. caanen M.D. i 
7 vo, with one copper-plate. Ext. from Acad. Sci., St. Louis, Vol. I, No. 
2.—This paper describes two new species of Codaster - 
tremites. The author shows —_— the mouth aperture and the ovarial 
apertures around it are each covered by a group of small 
calcareous. 
plates. The paper closes wi ein dabla-of the genera and species of the 
family Blastoidea found in the western and southern portions of the Uni- 
ted twenty-one species of Pentremites, 
(M’Coy), and one of erinus (Shum. and Yan.) Three of the 
Pentremites are from the Upper Silurian (Lower group); 5 
two from the ian aa from the Upper Hi and one from 
the Chemung); and om the Carboniferous (Su 
period); eight o i in ane Georita! limestone, and ei in the Ar- 
. chimedes limestone. Of the species of Codaster, two are Devonian (Up- | 
per Helderberg) and one Carboniferous (Encrinal limestone limestone). The specie 
of Eleutherocrinus is from the Upper moms 
) Lower Silu 
Son by E. J. ergs 
12 PP» — ene J ournal, Tobouts, for Mey, 1858.)—This is 
important paper, giving, with much detail a nd precision, methods se 
