ILLUSTRATIONS 



Page 



Frontispiece. Group in pl.aster il Inst rating (juarrj'-shop work 13 



Platp: I. ilaji of thi- Potomac-Chesapeake tidewater province 14 



II. Map of tlie Piny branch quarries 17 



III. Quarry-shop refuse exposed in the bank of the rivnlet 18 



IV. View looking north up the rivulet at the foot of the quarry slope.. . 19 

 V. View from the bed of the rivulet, showing exploitation pits 20 



VI. Section of quarry exposed by the first trench 21 



VII. Section of ancient pit filled with (juarry-shop refuse from above 22 



VIII. Chrracter of quarry-shop refnse at the fortyfourth foot 24 



IX. Face of the trench at the seventyseventh foot 26 



X. Character of refuse deposits at the seventyseventh foot 27 



XI. Pocket of refuse deposits at the seventyseventh foot 28 



XII. Portion of an extensi\ o deposit of shop refuse near the quarry face.. 30 



XIII. Section showing the irregular quarry face 31 



XIV. Roots of a chestnut tree growing in a bed of shop refuse 33 



XV. Section showing deposits filling the quarry exposed by the third 



trench 35 



XVI. Section showing the quarry face exposed by the fifth trench 37 



XVII. Quarry-shop rejects — progressive series 38 



XVIII. Blade-like rejects from the quarry-shop refuse 40 



XIX. Rejected blades of mo^it advanced form found in the quarry-shop 



refuse 40 



XX. Rejected blades of most advanced form found in the quarry-shop 



refnse 40 



XXI. Broken blades representing the most highly elaborated forms made 



in the quarry-shops 43 



XXII. Fragments of blades representing the most highly elaborated forms 



made in the quarry-shops 44 



XXIII. Relation of the flaked blade to the parent bowlder 44 



XXIV. Two specimens of flaked stone found in a single cluster 45 



XXV. Core-like forms from which flakes have been taken 47 



XXVI. Site of the Dumbarton quarry, showing refuse-covered slopes 49 



XXVII. Potomac bowlder bed exjiosed in grading U street 51 



XXVIII. Series of rejects from the South mountain rhyolite quarry 52 



XXIX. Rhyolite cache blades from a garden on Frogmore creek, near Haiti- 

 more 55 



XXX. Rhyolite blades from various caches 55 



XXXI. Quartzite cache blades from .A.nacostia and Bennings sites 55 



XXXII. Relation of specialized leaf-blade implements to the original blade.. 56 



XXXIII. Scraping implements of quartz and quartzite 56 



XXXIV. Series of flaked forms illustrating progressive steps in the manufac- 



ture of projectile points from quartzite bowlders 59 



XXXV. Quartzite blades of varying size and outline, mainly unspecialized, 



from Potomac village-sites 60 



XI 



