POSITION OF THE INSECT FAUNA. 



Insect fauna about the head of Narraganseti Bay — Continued. 



203 



STRATIGRAPHIC POSITION OF THE FAUNA. 



The discoverers of this interesting insect fauna appear to have done 

 little toward establishing the horizon or horizons in which it occurs, if it 

 has any assignable limits. The specimen of Etoblattina from Fenner's 

 ledge in Cranston, so Mr. Scudder quotes, was found "near the extreme 

 western upturned edge of the Carboniferous in the plumbago mining district, 

 and [is] therefore probably older than the others." 1 



The localities which have so far furnished these insect remains are 

 traversed by strata relatively low down in the Coal Measures section. 

 The outcrops in East Providence are in the horizon of the Tenmile 

 River beds. The shales of the Cranston series lying to the west of these 

 exposures are probably in part still lower in the section, extending down- 

 ward nearly to the base of the Carboniferous. It would appear, therefore, 

 that, so far as at present known, this fauna ranges from near the base of 

 the Coal Measures to and into the Tenmile River beds. The higher strata, 

 which have a nearly equal thickness, have not afforded fossils. The locality 

 at Bristol is somewhat in doubt as to its place in the section. 



ODONTOPTERIS FLORA. 



The flora of the Rhode Island Coal Measures, according to the list of 

 plants collected by the Rev. E. F. Clark and identified by the late Leo 



1 Op. cit., p. lt>. 



