L, Lesquereux on the Coal Formations of North America. 375 
13°45 = Long. 81° Long. 77°°5 
Lat. 39 31’ Lat. 39 07’ 
13°50 Long. 81° Long. 77°°5 Long. 74° 
Lat. 40 37’ Lat. 40 13’ Lat. 39 49’ 
13°55 Long. 81° Long. 77°°5 Long. 74° 
Lat. 41 48’ Lat. 41 19’ Lat. 40 55’ 
13°60 ~—- Long. 81° Long. 77°5 
Long. 74° 
Lat. 42 49’ Lat. 42 25’ Lat. 42 O17 
The observed and computed values of ¢, at the stations where 
the bar and cylinder were employed, compare as follows: 
; Observed 
: Station. observed. com uae — computed, 
Philadelphia, 13°45 13:50 -0'05 
Harrisburg, 13-44 13-50 -0'06 
Huntingdon, 13:51 13:52 0°00 
Homewood, 13-49 13-50 -O'O1 
Johnson’s Tavern, 13:54 13-4 +0°06 
Irwin’s Mill, 13-40 13-4 -O 
Baltimore 13-4 13:46 +0°03 
illiamsport, 13-5 13-55 000 
Curwinsvill 13-55 13-53 +0°02 
ercer 13°64 13-53 +O°1L 
rie, 13-57 13-57 0:00 
Ellicottsville, 13-97 13°59 +018 
ath, 13-72 13:60 +0°1 
Silver Lake, 13-47 13°58 -O'1r 
ilford, 13-50 13 56 -o'06 
Schenectady, 13°45 13°63 -o'18 
Syracuse, 13-61 13 63 -0'02 
Geneva, 13°63 13°62 +0 OL 
Niagara Falls, 13-64 13°62 +0°0 
Toronto, 13 84 13-65 ge 
The probable error of any representation is 0-066. 
Arr. XXXVIII.—On some questions concerning the Coal Forma- 
tions of North America; by Leo LesQuEREUX. (Continued 
m vol, xxxiii, p. 216. 
Concluding Remarks on the Fossil Ferns. 
THE examination of the fossil ferns of the coal, as far as it 
under review in the former papers,’ would apparently © 
Viz., their contour and nervation, the only P font generally pre- 
Served in the shales of the Coal Measures, 
* Vol. xxxii, p. 193, Sept., 1861, and vol, xxxiii, p. 206, March, 1862. 
