854 Recent Literature. [ August, 
been exploded by our geologists as accounting for our Pennsyl- 
vania anthracites, for there are no trap dyke exhibitions within 
many miles of the anthracite basins. We shall await with some 
impatience any explanations which Ashburner will be able to 
prove with the facts which he is gathering. 
A most remarkable thickness of coal is observed in one of the 
sections of the Mammoth bed measured in the vicinity of the 
“Old Lehigh Summit Hill mine (quarry).” The thickness per- 
pendicular to its bedding is 114 feet, with 106 feet of workable 
coal, yet 9I feet away the bed measures only 73 feet thick with 
but 66 feet of coal. As great a change is observed in the thick- 
ness of the coal measure, sandstones and conglomerates (Pottsville 
conglomerate No. xu, or Millstone grit), from the bottom of the 
Mammoth bed down to the top of the Mauch Chunk red shale, 
No. xı (representative of the Mountain, St. Louis, Chester, and 
Lewisburg, Va., limestones), At Tamaqua these strata measure 
1700 feet thick, at Lansford, only five miles to the east, they only 
measure 900 feet thick, while at the old Hacklebarney tunnel, 
back of Mauch Chunk, eleven and a half miles east of Tamaqua, 
and six anda half miles east of Lansford, they have thickened 
again to 1550 feet. This is a fact quite inconsistent with all pre- 
vious views which have been held in regard to the structure of the 
carboniferous conglomerate in the anthracite region. Ashburner 
offers no explanation other than in a note placed on the sheet which 
says that it “ may show a non-conformability between the conglom” 
erate and the underlying Mauch Chunk red shale No. x1, * 
or a non-conformability between the individual strata forming the 
conglomerate measures.” We understand that the facts devel- 
d to the 
Coves-Stearns’ New Encranp Biro Lire! —Wit 
pletion of the second volume of this work, the incipien 
1! New England Bird Life, Being a manual of New England Ormia Coues, : 
; 
vised and edited from the manuscript of WINFRED A. STEARNS by ee 
ar II. Non-oscine Passeres, birds of prey, game and water Birds, 
Shepard; New York, Charles T. Dillingham, 1883. 12mo, pp. 409- 
ith the com- l 
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