S. H. SCUDDER ON PALAEOZOIC COCKROACHES. 35 



The American species come from the following localities, the Mylacridae being placed in 

 the left hand, the Blattinariae in the right hand column. 



ACADIAN COAL-FIELD. 

 Sydney, Cape Breton. 



Mylacvis bretonense. Petrablattina sepulta. 



" Heeii. 



Pictou, Nova Scotia. 



Arcbymylacris acadicnm. 



APPALACHIAN COAL-FIELD. 

 Gannelton, Beaver Co., Perm. 



Mylacvis pennsylvanicum. Archymylacris parallelling 



" Mansfiekli. 

 Necymylacris heros. 



Pittston, Luzerne Co., Penn. 1 



Lithomylacris angustnm. Etoblattina Lesquereuxii. 



" pittstonianura. Gerablattina fascigeva. 



Necymylacris lacoanum. 



Cassville, W. Virginia. 



Gerablattina balteata. 



Bellaire, Obio. 



Gerablattina balteata. 



EASTERN INTERIOR COAL-FIELD. 

 Danville, 111. 



Lithomylacris simplex. 



Colchester, III. 



Mylacris anthracophilum. 



WESTERN INTERIOR COAL-FIELD. 

 Frog Bayou, Arkansas. 



Etoblattina venusta. 



The correlation of the beds in the Eastern border and Interior basins of N. America is 

 not yet satisfactorily accomplished. The period of the deposition of the millstone grit in 

 the interior basin may even possibly be synchronous, I am informed by Professor N. S. 



1 Concerning the localities in the vicinity of Pittston, Mr. impregnated with carbon. The specimens came from Port 

 R. D. Lacoe, to whom I am indebted for all 1 the specimens Griffith at the outcrop of the shales at one of the prin- 

 described from there, writes me that the shale containing cipal anticlinals that cross the otherwise quite level coal 

 Etoblattina Lesquereuxii was picked up in the Vicinity of field, and once apparently formed long narrow islands in the 

 Pittston, in a pile of culm or impurities from a mine; the carboniferous lake, against the southeastern side of which 

 exact locality was unknown to him, but from the character many small objects drifted and left their impress. Gera- 

 of the slate he had no doubt of its being from the roof shales blattina fascigera was found by Mr. Lacoe in the anticlinal 

 of the D seam of anthracite coal. Lithomylacris angustum next north of the one first mentioned and also on the southl- 

 and L. pittstonianum are from the roof shales of the E seam eastern side. Necymylacis lacoanum comes from the lowest 

 of coal, which when unaffected by weathering much re- productive coal measures near Pittston. 

 semble the shales of the D seam, but is very rarely so highly 



