14 



SMITHSONIAN MISCELLANEOL'S COLLECTIONS VOL. 63 



considerably, as shown in hgiire i6, but the even skyhne of the ancient 

 ])lain is still clearly evident. 



( )ther factors in the geologic history of Maryland are recorded in 

 the well detined gravel terraces along the major streams of the area 

 and in great alluvial fans of large and small bowlders, spreading out 

 at the foot of the larger mountains and sometimes reaching a depth 

 of 150 feet. All of these phenomena have been plotted and will 

 form a part of the geologic map of the region. 



Fk;. 16. — Dissected l-"arly Tertiary ( Harrishur.y ) peneplain, west of 

 town, Marxland. Pliotograpli hv Bassler. 



COl.Td-XTlXG Fd.SSIL ECHIXODI'IRMS IX ILLlXcnS 

 The s])ecial held ex])lorations maintained by Mr. Frank Springer, 

 associate in paleontolog\' in the I'. S. National Museum, were con- 

 tinued during the season of 191 3 l)y his private collector, Frederick- 

 lira vul 1die pur]iose of these explorations is to obtain additional 

 material for use in Mr. Springer's monographs upon the fossil cri- 

 noidea, now in course of ])reparation, but thev also result in important 

 accessions of excellent s])ecimens for the completion of the exhibi- 

 tion series in the hall of lnvertel)rate Paleontology in the Xational 

 Museum. 



