70 Scientific Intelligence. 
now being brought up;” and that the whole depth from the sur- 
ee 
The overlying Eocene consists of the Lower Eocene or Buhr- 
ogee group, which has a thickness at Aiken of 200 feet and rests 
n the granite, and of 250 feet at es the Middle or 
Bautce beds, which have a thickness of 300 feet at Charleston, 
and were formerly known as the Calcareous beds of the Charles- 
ton basin; and the Upper, which includes the Cooper and faney 
groups, soit 300 feet thick in the Artesian boring. Next c 
the later Tertiary, called by Lieutenant Vogdes Pliocene, which 
rests upon the Cooper group, and at Goose Creek is about ‘12 feet 
thick; it is stated to contain 45 per cent of recent shells. 
Yi ucatan Coral Reefs, and ous elevated Coral Rock.— Prof. 
A. Agassiz, in his “ Letter No. 1” on “ Dredging operations of the 
U. 8. Coast Survey, Schooner ‘Blake,’ during parts of January 
and February, 1878,” describes the coral reefs of the Yucatan 
coast and land, and also the life of the sea bottom from there to 
the Florida Reefs. He states that the fauna of the Yucatan bank 
is identical with that of Florida. Alacran reef, on this bank, is 
an atoll, elliptical in form, about 14 miles long ‘and 8 wide, with 
a depth of 1 to 6 fathoms inside, where are growing over the 
serge parts “huge masses 0 Astrea, Gorgonia, Meandri rind, 
d Madrepora palmata, which occasionally ris e to the surface.” 
The reef is steep to the eastward and s ae gradaatly to the west- 
war e structure is identical poe ge t of the main Florida 
reef, and those of the northern coast of Guba In Cuba evidence 
of great elevation is seen in the orice of ancient ote ea in 
the hills surrounding Havana and extending to Mat these 
hills being 1200 feet high and ote entirely of pe 9 Gdeuical 
in sag s with those now livin 
Large numbers of siliceous sponges were brought up on the 
Cuban frre the living Favosites, “ perhaps the most interesting 
coral ever dre edged,” together with many of the corals collected 
by Count Pourtalés on “the rocky plateau south of the Florida 
aera in 200 _ 300 fathoms. 
The mond Bowlder Trains.—These trains of bowlders, 
diet made esgare by Dr. Stephen Reid, and described by Prof. 
Edward Hitchcock and later by Lyell, have been studied with care 
by E. R. Benton, and a description and map of them, with an ex- 
cellent discussion of the facts, os peusained in Bulletin Nos. 2-3, 
of oe v, of the Museum of Comparative Zoology, Cambridge, 
1878 
o synchronise ( 
a Cleveland; a which "hake based his subdivisions. This 
section is as follows, beginning with the summit of the series: 
