174 DR. THOMAS STERRY HUNT ON THE 
serpentine-outcrop on the west side of New York city has a strike which would carry it to 
the east of Staten Island, and probably corresponds to a repetition of the same belt. 
Gneissic rocks are met with in a boring near the serpentine at Hoboken, and are found in 
the small islands between Manhattan and Staten Island, so that there can be no reason- 
able doubt that the serpentines of Staten Island and of Hoboken belong, like that of 
New York city, to the gneissic series of the region. The determination of the precise 
relations of these gnessic rocks to those accompanying the serpentines of eastern Penn- 
sylvania, already described, remains for farther inquiry. 
§ 25. We have next to notice the occurrence, in Pennsylvania, of serpentine in the 
Lower Taconic rocks of Emmons, the Primal slates of Rogers, which he supposed to be- 
long to the horizon of the Potsdam of the New York series. In accordance with this view, 
we find that in a report by Genth on the mineralogy of Pennsylvania, in 1875, the oceur- 
rence of serpentine is mentioned, though without any details, in the “ Potsdam sand- 
stone” near Bethlehem, at the iron-mines of Cornwall, and also in the township of 
Warwick, Chester county. * This statement is, however, misleading, inasmuch as the 
serpentine is not found in the sandstone-rock which has been conjectured to be the equi- 
valent of the New York Potsdam, but in certain schists and limestones, referred, rightly 
or wrongly, to the same geological horizon, the so-called Primal slates. 
§ 26. I have had an opportunity of observing the occurrence of serpentine at Corn- 
wall, where it forms small irregular masses disseminated in a bed of crystalline limestone, 
itself subordinate to the great mass of crystalline schists which include the magnetite 
largely mined at this locality. Serpentine, generally with limestone, is found at many 
other localities associated with iron-ores at the same geological horizon, as at Fritz’s Island 
and elsewhere, near Reading, at Boyerstown, and at the Jones iron-mine, near to Warwick, 
where it is found in small lenticular masses imbedded directly in the crystalline schists 
which, as at Cornwall, include the cupriferous magnetites of the region. These schists 
include hydrous micaceous minerals, among which are chlorite, and the geeenish foliated 
silicate of copper, magnesium and aluminum, to which [have given the name of venerite. 
The manner in which lenticular masses of pure serpentine, sometimes only a few 
ounces in weight, are found imbedded in these schists, not less than the mode of their 
occurrence in the limestones at this horizon, is such as to suggest very forcibly the notion 
that they have been formed under conditions not unlike those which have given rise to 
chert or to iron-stone nodules. No large masses of serpentine have, so far as known, been 
found at this horizon, yet they may be expected. 
§ 27. We have next to notice the existence of a bed of serpentine at Syracuse, New 
York, which was, in 1839, examined and described by Prof. Vanuxem, then engaged in the 
geological survey of the State. The locality, “on the Fort-street road to the east of Syracuse” 
or, according to Dr. Lewis Beck, “on the hill a short distance east of the mansion of Major 
Burnet, at Syracuse,” has long since been concealed by the growth of the city, and we 
have, so far as I am aware, no other description than those given by Prof. Vanuxem in 1839 
and 1842, + of which, on account of the interest and significance of this curious 

* Second Geological Survey of Penn., Report B, p. 115. 
+ Vanuxem, Third Annual Report on the Geology of the Third District of New York, pp. 260 and 283 ; also 
Final Report on the Geology of the Third District, pp. 108 and 110, and Beck’s Mineralogy of New York, p. 275. 

