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the two rocks, are wanting. The calciferous, moreover, rests uncon- 
formably upon the gneiss; great discordancest exis in the paralleHsm of 
their lines of separation or division. In some localities, the lower lay- 
ers show marks of chemical action, as mentioned in the report; in others, 
as at the paper-mill in Herkimer, they contain rolled stones of vitreous 
quartz. Fossils, other than fucoids of the largest species, are exceed- 
ingly rare. I found but two or three specimens; they were casts of small 
spiral univalves, too imperfect to admit of a knowledge of either species 
or genera; likewise, two fragments belonging to Crustacea. All these 
specimens were found in an upper layer of the rock. 
" Birdseye LimestmeP — This rock contains fragments of the calcife- 
rous at Marcellus' quarry, near Amsterdam. We find also at some other 
places, for instance the falls in Flat creek, parts of upper layers made up 
of rounded fragments of its own mass, cemented by a more light colored 
limestone. 
The birdseye is highly characterized by the vertical stems of the fu- 
coides demissus. Other fossils are rare; the one usually met with is the 
orthostoma communis and the orthocera dupleXo 
Trenton Ldmestone. — The bottom of the lower layer of this limestone, 
at the quarries west of Little-Falls, is in part made up of round and 
elongated fragments of the birdseye. Well formed pebbles of the same 
occur in the limestone at Tribes' Hill. Its fossils are exceedingly nu- 
merous. Of undescribed genera there were two collected, the Trocolites 
ammonis and the Phragmolites compressus, and one species of a new Or- 
this, the glabella. This limestone is readily distinguished from all the 
other rocks, by the numerous individuals of the Leptaena alternata, Del- 
thyrus striatula, Orthoceras striatus, Eellerophon apertus, Favosites 
5 Calymene blumenbachii, Cryptolythus tessellatus, Isotelus gigas 
and Cyclops. 
Black Shale. — Contains no fragment of any rock. It is remarkable 
for being the floor or surface through which the preceding rocks, at a 
comparatively recent period, have been thrust or protruded. Its com- 
mon fossils are three small species of fucoides, the F. dentatus, F. se- 
via, and F. scalarius. Paradoxides beckii, Lingula ovata, and a com- 
pressed involute univalve, resembling the trocholithus ammonis of the 
Trenton limestone. 
Green Shale and its Sandstone. — This group is variable in its characters, 
in different counties, appearing as a dark coloured sandstone in Montgo- 
mery, with but little shale. In Herkimer, as a green shale, with but lit- 
