354 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
CONCLUSIONS. 
1. The coral reefs exercised a controlling influence in the develop- 
ment of Gotland lithology and stratigraphy. 
2. Little reHance can be placed on coral reef faunas in correlation, 
since species of different horizons are apt to occur in association. 
3. The fauna of any basin about a coral reef is apt to exhibit many 
differences when compared with the fauna of another basin. 
4. Discordances of strata are readily developed in sedimentation 
about coral reefs and have little or no significance. 
5. Conglomerates and worn shells should be present in deposits 
about coral reefs, and neither indicates a transgressing sea nor a land 
interval. 
6. Directional and quantitative variations of inclination of strata 
have wide limits about coral reefs, and should always be considered 
in coral reef stratigraphy. 
7. In general, the rock of any reef is older than that lying at the 
same level on its flanks. 
8. Strata of the same time interval will lie at different elevations in 
the different channels between the reefs. 
9. The ultimate solution of the problems of Gotland stratigraphy 
will probably be reached by a study of the relations of the sediments 
and the faunas to the coral reefs. 
