10 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. IO3 



Yuma at San Jon has an elongated subtriangular shape with slightly 

 convex edges, a rudimentary tang formed by a slight inset on the 

 edges near the base, and a slightly convex base (fig. 2, c). There is 

 a suggestion of the median ridge on the faces and the inset edges near 

 the base are smoothed. All the Yuma points reported from the site 

 have not been seen by the writer as some of the earlier finds have 

 been scattered, but those that were studied conform to the above 

 description. It is possible that some of the Oblique Yuma (Worming- 

 ton, 1939) may be there, although the presence of one form does not 

 necessarily imply that the other also will be found. There are 

 numerous cases where only one of the types occurs at a site. 



The third type of point, one with a long, leaf-shaped blade, round- 

 ing shoulders, and a roughly straight tang with a slight bevel to the 

 left, and a concave base (fig. 2, b), is found at a little higher level 

 in deposits essentially the same as in the case of the preceding form. 

 This point suggests some of Ray's Clear Fork types (C. N. Ray, 

 1938), belongs in the same category as one from the Taos Plateau 

 reported by Bryan and Butler (1940), possibly has some relationship 

 to Sayles' Brazos River forms (Sayles, 1935), and also bears some 

 similarity to points from the Big Bend region identified as forms 

 frequently found in Pecos River sites ^ (Kelley, Campbell, and 

 Lehmer, 1940, pi. 5, fig. i, b, upper left; fig. 2, b, left) ; ye{ it is 

 sufficiently different to make correlation with the latter questionable. 

 The only animal remains associated with these points are those of 

 modern bison, the bones showing no traces of fossilization. The 

 chief distinction between the remains of this and the Yuma horizon 

 appears to be in the fossilization of the bones. In general the degree 

 or absence of mineralization has little value as a criterion because 

 of the varying rates at which it takes place under diverse conditions 

 and in different localities. When the material comes from a small 

 area at a single site where there is no difference in conditions, how- 

 ever, it probably does have some significance and can be considered 

 as giving at least an indication of relative age. Hence on the basis 

 of the nature of the bones and of the earth from which they and the 

 points were dug it seems evident that they are somewhat, although 

 not markedly, later than the Yuma. 



The fourth type in the series is actually a group of several subtypes 

 of the small, notched and tanged arrowheads common at recent Indian 

 sites. Sporadic examples are found on the surface around the basin, 

 on the slopes of the brakes, and on the plain below. In the excava- 



^ Not the type of point named the Pecos River point, however. 



