Mineralogy and Geology. 119 
beaks, on the inner side of the valves, is a common feature in such Car. 
boniferous species as Wuculana bellistriata (=Leda bellistriata of Ste- 
ns), His Nucula rectangula, of the same plate, is more probably a 
Nuculites. 
On Plate IX, fig. 1 represents his Pentamerus bisinuatus, which is ap- 
perenuly only a variety of the well known P. oblongus. On the same plate, 
e figures a shell at first described by him under the name Ambonychia 
neglecta, but placed by him now in the genus Pierinea. It has not the 
strung anterior muscular scar, nor apparently the posterior hinge teeth of 
Pterin nea, however, and until the characters of its hinge can be clearly de- 
termined, it would. have been better to leave it in the genus Ambonychia, 
are generally sufficiently clear to enable the paleontologist, by the aid of 
the figures, to identify the forms described. The author also deserves 
‘eredit for having published accurate figures of most of the species pro- 
posed by him, an nd it is to be ho oped that he will publish figures of the 
others, so that all may form their own conclusions as to which of them 
should be adopted, and which arranged in the lists of synonyms. 
must confess, however, that a careful study of his memoir has not left. a 
very favorable impression in regard to the author's powers of discrimina- 
tion, nor of his knowledge of the literature of the subject upon which he 
has essayed to write. 
F a Mont Alto Lignite and Appalachian Erosion ; by J. P. Lester. 
0 pp., ao with 4 plates. (From the Proc. Amer. Acad, Sci., 1864, 
a 463—482.)—Mr. Lesley here describes a bed of lignite found recently 
in Southern Central Pennsylvania. He regards it as of the same age 
with the lignite of Brandon, Vermont, described by Prof. Hitchcock, 
but not connected in any way | with the iron ore (limonite) beds with 
which the latter associates them 
Mr, Lesley enters at some length in into the nature and origin of the 
ore-bed formation of the Atlantic border, and the position of the lignite, 
from which we cite the followin ng: 
“Tt consists every where of two parts, more or less easily distinguished ; 
the one stratified in the same sense as the Silurian limestones themselves ; 
the other a surface-wash over the basset edges of the first. The i of 
the formation of this local surface-wash may be Tertiary, and 
Post-tertiary. The stratified portions must be, as to their ratetion, of 
Lower Silurian age; while the metamorphism which sg have undergone, 
in situ, productive of stratified clays and ores, may date from any time 
subsequent to the formation of a surface-topogra Bed pater iden- 
Silurian calcoferriferous sandstones and slates, in situ, at their outcrops, 
into limonite clay beds, in ipso situ, stratified as before, but charged with 
* These limonite beds were long since shown fe te Pesca to 
contrary to the views of Pro f. Hitchcock, altered beds of p: 
‘erous, micaceous 
‘ schist in poponn See his Report (1842), p. 139, and ale tis Jour 
nals [3 268 ii, 268, 1846.) ; 
