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PALAEONTOLOGY OF THE SURVEY. 
ECHINODERM. 
ASTKODAPSIS, Conrad. 
Asxrodapsis Antiselli, PI. 10, figs. 1 & 2. —Pentangular, suboval; disk with 5 broad angular 
profound depressions ; ambulacra not greatly curved, open at the marginal extremities ; apex 
central or subcentral, beneath flat, or slightly depressed, with 5 distinct furrows ; anus sub¬ 
marginal. 
Locality . —E st rella. 
Masses of limestone appear to be composed chiefly of the fragments of this species, and con¬ 
tain many entire, but apparently water-worn specimens. In this respect it resembles a Miocene 
rock on the Patuxent river, Maryland. Length, If inches. 
