192 E. M. KINDLE 



This lower zone lies 480 feet, and the second zone 1,380 feet, 

 above the Genesee shale, so that the species in this section has a 

 known range of 900 feet. 



In the Hollowing Run section, which lies about 25 miles south- 

 west of the Catawissa section, R. laevis was found at only one 

 horizon. Its occurrence in this section is not far from the horizon of 

 the lower R. laevis zone in the Catawissa section. 



In Pennsylvania the Naples and Ithaca fades of the Nunda hold 

 the same geographic relation to each other that they do in New York, 

 the first occupying the westerly, and the second the easterly, sections 

 of the Nunda. The Altoona section, which has been studied by Mr. 

 Charles Butts and the writer, lies well to the west of the Susquehanna 

 sections, and within the area of the dominance of the Naples facies. 

 Neither R. laevis nor any other faunal element of the Ithaca facies 

 was found in it. The limitation of the known occurrence of R. laevis 

 to two sections is doubtless due to the fact that these are the only 

 sections which have been carefully studied within the area where this 

 species may be expected to occur. It is safe to predict that R. laevis 

 will be found in many of the more easterly sections of the Nunda 

 from the New York to the Maryland line, and that it will not 

 generally be found in the westerly sections. 



A collection of fossils from West Virginia recently submitted to 

 the writer by Mr. George Stose for determination contains two speci- 

 mens of R. laevis.'' They occur in association with a brachiopod 

 fauna representing the Ithaca facies of the Nunda. They were col- 

 lected on Yellow Spring Run, 3 miles southeast of Berkley Springs, 

 W. Va. Mr. Stose's collection represents the most southerly occur- 

 rence of the species which has been discovered. The determination 

 of these West Virginia specimens gives the species a known distri- 

 bution in a northerly and southerly direction of about 225 miles. 

 In New York its distribution in an easterly and westerly direction 

 appears to be limited to about 60 miles. In the southern part of its 

 range we have as yet no data for determining its distribution in this 



I The Hancock quadrangle in which this species was found is being surveyed 

 co-operatively by the Maryland and United States Geological Surveys, and the 

 writer is able to publish these data through the courtesy of Professor W. B. Clarke, 

 director of the Maryland Geological Survey. 



