11 
to ascertain. It was probably obtained in Ulster 
County, among the fragments of sandstone, rolled 
from the Shawangunk mountains, and which are so 
rich in fossil remains. 
Asapuus AsTraGALotes.* Green. Cast, No. 37. 
Clypeo? corpore granulato ; costis latis, striatis et 
valde distinctis ; caudaorbiculari. 
We have met with a perfect fragment of the ab- 
domen and tail only, of this striking Asaph. It com- 
prises four distinct costal arches of the lateral lobes ; 
these are terminated by a narrow well defined mem- 
branaceous expansion along their outer edges. The 
ribs are broad and faintly grooved on their upper sur- 
face ; the middle lobe is rounded—exceedingly prom- 
inent, and terminated rather abruptly near the central 
part of the membranaceous expansion, which appears 
to be supported by a thin short prolongation from it, 
as in the A. micrurus. The upper surface of the 
whole animal, appears to have been covered with mi- 
nute granulations. 
The fossil from.which our description is made, I 
observed in the fine cabinet belonging to the Lyceum 
of Natural History in the city of New York. There 
is a number of specimens of this species, in that im- 
portant, extensive and liberal institution ; but they 
are all fragments, presenting the same general appear- 
* In allusion to:its remarkable vertebre. 
