PAPERS ON GEOGRAPHY AND GEOLOGY 333 



Rangia cuneata Gray. Marine Clam. Left valve of a 

 medium sized specimen found at a depth of 12 feet in 

 James Ramey Mound. Also found with surface material. 



Margin ell a apicina Menke. This small marine snail 

 occurred in abundance, especially in the James Ramey 

 Mound. This species was used largely for the purpose 

 of making beads, the side of the shell being ground down 

 to the natural cavity, as in the case of the fresh water 

 shells Anculosa and Campeloma. The number of speci- 

 mens found indicates that this shell was a favorite for 

 this purpose. A singular fact, through perhaps without 

 significance, is that these shells were found only in the 

 James Ramey Mound, none occurring in any of the burial 

 mounds thus far examined. In the mound mentioned 

 f hey were found at several levels between 1 and 12 feet 

 _,elow the summit, and from 20 feet deep to the base of 

 the mound, 23 feet below the summit. 



Ten species of marine shells have been found in these 

 mounds, all but one being gastropods. Three of these 

 species were used definitely for ornamentation, either as 

 beads, nose ornaments, or gorgets. It is possible that 

 these other species will be found to have been used for 

 the same purposes when other mounds are examined. 



COMPARISON WITH HOPEWELL MOUNDS OF OHIO 



It is of interest to compare the mollusks found in the 

 Cahokia group with those preserved in the Hopewell 

 group of mounds in Ohio (Moorehead, Publication 211, 

 Field Museum of Natural History, 1922). An examina- 

 tion of the collection on exhibition in the Field Museum 

 shows that apparently only four species are common to 

 both mound groups, Busycon perversa, Fasciolaria gi- 

 gantea, Cyclonaias tuberculata and Amblema costata, the 

 last two fresh water mussels. 



Two large and characteristic species of Mollusca occur 

 in the Hopewell group that are absent from the Cahokia 

 group, Cassis madagascariensis, and Cypraea exan- 

 thema. This may indicate a different trade route, per- 

 haps with different tribes, because these shells would 

 appeal to the aboriginal mind on account of their size 

 and striking appearance as well as attractive colors, and 

 would have been sought eagerly by the Cahokia people. 



