292 
had made its way up to Fishkill, for there he had gathered it 
someway out of the Hudson and up Fishkill Creek, m a 
perfectly healthy condition and lively in its movements. 
But the deposit exhibited by Prof. Martin is of a different 
character from any of those mentioned, and doubtless con- 
tains the remains of marine species only. Several years since 
a friend, residing in South Brooklyn, called my attention to 
the fact that at a point at Gowanus where the streets had, dur- 
ing the extension of the city, been built of refuse stone 
across a portion of a former marsh or estuary, that, a consid- 
erable amount of the heavy superincumnbent material had 
sunk down, crowding up along its side, the ancient bed of. 
the marsh. This inverted material was suspected to contain 
the remains of Diatomacez and examination by means of the 
microscope revealed the fact that such was the case. But 
visiting the locality, it was found that a miniature chain of 
mountains had been raised for many feet along the line of 
two of the streets and the raised material being split open 
along its ridge revealed the stratification of the ancient marsh- 
bed. At top there was the gravel or new material which had 
lately been brought to the spot. Below this was a kind of 
peat consisting of the matted roots mainly of Zostera Marina, 
beneath which was a stratum of a light, greyish colored sub- 
stance consisting almost entirely of Diatomaceous exuvia- 
Farther down wasa layer of littoral shells, oysters, clams and 
the like, whilst the whole was underlaid by the coarse, sea- 
shore gravel common along the coast. At some future time 
the results of the examination of this deposit by means of the 
microscope will be made public. At the back of the town of 
Hoboken, N. J., is a brackish marsh which has been for years 
a favorite hunting-ground for microscopic-object hunters. 
Ever since the finding of the Gowanus deposit I have expect- 
to see the same process of inversion of this marsh take 
place. Within this winter I have observed that streets have 
been extended from Hoboken across this marsh and in one 
place a crowding up has taken place and a material very sim- 
ilar in appearance to that found at Gowanus brought to 
light. All of these cases of marsh inversion are of interest to 
