214 THE DEVONIAN OF MISSOURI. 



One of the important facts which is established by these 

 tables, is the close relationship which exists between the Little 

 Saline fauna, and that of the upper Oriskany of New York state, 

 although some of the Missouri specimens do not attain so large a 

 size as do examples of the same species in New York. Of the 102 

 which have been identified, 51 are the same or show 

 close affinity with New York species, 18 of these with Helder- 

 bergian, 31 with Oriskany, and 8 with Onondagan species, this 

 latter group all being present in the upper beds. These are: 

 Cystodicya cf. rigida, Dalmanella lenticularis, Stropheodonata cf. 

 inequiradiata, Centronella giansfagea, Spirifer cf. varicosa, Platy- 

 ceras dumosum, Ceratolichas gryps and Phacops cristata. 



Of almost equal importance is the relationship existing 

 between the Little Saline fauna, and that from the Lower Devon- 

 ian of Maryland, 44 species in all being definitely recognized as 

 identical or closely allied. Of these 21 are Helderbergian, and 31 

 are Oriskany species. Notwithstanding the greater distance 

 separating the two regions, a surprisingly close resemblance is 

 also recognized between Little Saline fauna and that of the Grand 

 Greve limestone of Gaspe in far eastern Quebec, eighteen species 

 are definitely identified with Grand Greve forms, while 6 show 

 a close resemblance. 



Less decided, but still quite marked, is the relationship 

 existing between the Little Saline fauna and that from the Lower 

 Devonian of Tennessee. Eight species are identified with, or 

 show an affinity with Linden forms (Helderbergian), while 16 are 

 identifiable, with forms from the Harriman chert and Quail 

 limestone (Oriskanian). The fact that the Missouri fauna bears 

 a closer resemblance to that of the more distant Appalachian 

 trough than to the closer Tennessee an forms is surprising, since 

 the entire trough seems to have served as a pathway for migra- 

 tion and environmental conditions within the limited south- 

 western part probably were similar. 



