ILLUSTBATIONS XV 



Page 

 Figure 21. The principal percussive methods of stone flaking 134 



22. Adventitious origin of the crescentic edge and the gouge shape of 



the pebble nucleus 135 



23. Examples of flaked pebbles from Argentina and District of 



Columbia 136 



24. Chipped implements of black jasper (Arroyo Corrientes and 



Necochea) 137 



25. Spikelike forms of black jasper pebble derivation, possibly rejects 



from arrow making (Miramar and Necochea) 137 



26. Scrapers of jasper (Necochea and Monte Hermoso) 137 



27. Nucleus of quartzite from which flakes have been removed 



(Campo Peralta) 139 



28. Arrow points of quartzite (Campo Peralta) 139 



29. Quartzite scrapers of duck-bill type (Campo Peralta and Neco- 



chea) 139 



30. Hafted Tehuelche scraper of duck-bill type, made of green bottle 



glass (Hatcher collection, southern Patagonia) 140 



31. Plano-convex blades of white quartzite, showing the carefully 



chipped convex faces and the profiles (Camjjo Peralta) 141 



32. Narrow high-liacked blade of quartzite (Laguna Malacara) and 



sjiikelike form of c^uartzite (Playa Peralta) 141 



33. Quartzite muller-iiestle of exceptional size and shape (Campo 



Peralta) 142 



34. Pestle of gritty sandstone (Mar del Plata) 142 



35. Mortars of sandstone (San Bias District and Viedma) 143 



36. Mullers: Granite, well-polished (Viedma); sandstone (San Bias 



District) 143 



37. Pestles: Quartzite pestle of cigar shape (San Bias District); sand- 



stone pestle, fragment (San Bias District) 144 



38. Axlike blade of sandstone, bearing engraved design (Puerto San 



Bias) 144 



39. Hammer-anvil of quartzite, used secondarily as a muller (Viedma) . 145 



40. Leaf-shaped blades of brown jasper, probably rejects of manufacture 



(San Bias) 145 



41. Series of jasper leaf forms representing successive steps in the spe- 



cialization of arrow points (San Bias) 146 



42. Drill-point of jasper (San Bias) 146 



43. Teeth from the Carcarana skull. (After Gervais) 186 



44. Transverse section of the stream Frias, demonstrating the geological 



constitution of the strata at the point where the fossil man of 

 Mercedes was found, together with a plan of the excavation made 

 in exhuming the remains 199 



45. Skull of Arrecifes, norma ZateraZis. (After Lehmann-Nitsche) 227 



46. Skull of Chocori, norma lateralis. (After Lehmann-Nitsche) 240 



47. Ovejero skull No. 2 (side view) 248 



48. Tibia of Baradero: Transverse section of the shaft 261 



49. Lower jaw of modern man, showing only a slight chin prominence; 



unidentified, but either white or Indian.. 285 



50. Norma lateralis of Dijyrothomo fragment and Ameghino's " comple- 



tion" of such fragment, compared with norma lateralis of Alsa- 

 tian skull. (After Schwalbe.) 339 



51. The Monte Hermoso femur 370 



