Woodworth—Dinosaur tracks in New Jersey. 481 
residue, consisting mainly of basic carbonate of magnesia. It 
is decomposed with effervescence in cold dilute hydrochloric 
acid, with slight residue insoluble. 
A careful qualitative analysis of crystal fragments showed 
it to consist essentially of sodium, magnesium, hydrochloric 
and carbonic acids, indicating a double chloride and carbonate 
of sodium and magnesium. Traces of phosphoric acid, silica, 
iron, calcium and organic matter were also found. This com- 
position is quite as remarkable as that of other species peculiar 
to the Borax Lake region. 
The name “ WVorthupite” is proposed for this new species, 
since it was entirely due to Mr. Northup’s indefatigable zeal 
in collecting that the mineral was brought to light. Professor 
Penfield has promised to make a quantitative analysis of this 
and several other interesting minerals found in association, at 
least one beside the Northupite being new. 
ArT. LIV.— Three-toed Dinosaur tracks in the Newark 
Group at Avondale, NV. J.; by J. B. Woopworta. 
A “track stratum” appears first to have been recognized in 
the quarries along the west bank of the Passaic River, in New 
Jersey, in the Newark rocks, by Mr. Frank L. Nason, of the 
N. J. Geol. Survey, in 1888. [n his description, the general 
stratigraphic relations of these quarries are set forth, but 
nothing more is said regarding the tracks other than that they 
are referred to “reptiles, birds and insects.” * 
The object of this notice is to confirm Mr. Nason’s observa- 
tions as to the existence of tracks, and to describe a track- 
covered slab seen in the quarry at Avondale in September of 
this year. Having come fresh from the collection of dinosaur 
tracks at Amherst, the writer began a search in the now little- 
worked Newark quarries. [Il]-defined impressions were here 
seen, but nothing that was satisfactory. At Avondale, mark- 
ings, due neither to current-mark nor to ripple-mark, were at 
once seen on the brownish-red shale-covered surfaces of several 
blocks of freestone. In addition to these equivocal impres- 
sions, the following described foot-prints are essentially identi- 
eal with those found in the Connecticut valley area: 
On a triangular block about 7 feet on a side, 15 tracks were 
seen. These were of two kinds, with the exception of one 
isolated print, in three lines as follows: 
* Annual Report of the State Geologist for 1888, Camden, 1889, pp. 22, 28. 
