REPORT OP THE STATE PALEONTOLOGIST 1902 937 



of these faunules, but, as a few specimens of Dictyonema 

 flabelliforme have been obtained from the Clonograptus 

 beds, it is provisionally assumed that the faunules belong 

 together as parts of a larger fauna and do not indicate sharply 

 separated horizons. 



The author and Mr van Ingen were not successful in determin- 

 ing the interval of rock between the two principal fossil beds or 

 the thickness of the series of strata. All that could be established 

 was that in one place the bed with Clonograptus is connected with 

 a series of alternating black and olive-green slates, the latter char- 

 acterized by worm tubes, which series has a thickness of 15 feet; 

 that in another place a Clonograptus bed, presumably the same, 

 is found overlying a series of 20 feet of like slates, which alternate 

 with two series of thin, barren limestone bands [see pi. 2, which 

 shows the lower series of limestone bands]. The principal 

 Dictyonema horizon occurs in a iy 2 inch band of peculiar lith- 

 ologic character, it being a soft, strongly ocher-spotted black mud 

 shale, which has a highly developed and, for the paleontologist, 

 very unfortunate system of contraction joints. This band is sepa- 

 rated by about 10 feet of black or greenish slates from a series of 

 thin limestone bands in about the same number as that men- 

 tioned in connection with the Clonograptus bed. It is, hence, 

 to be assumed that these two series of limestone layers are iden- 

 tical, and that the series of rocks containing these beds is at 

 least 30 feet thick, but most probably considerably more. The 

 fine black mud shale intercalated between the thin limestone 

 bands, contains in another place great numbers of early 

 growth stages of Dictyonema. 



The principal Dictyonema stratum has been found to contain 

 these fossils in such numbers that all surfaces of the thinly bedded 

 band are entirely covered by colonies of Dictyonema fla- 

 belliforme Eichwald, forma typica ( =D. s o c i a 1 e Sal- 

 ter) and var. acadicum. On a slab of similar lithologic 

 character, lying loose on the bed, a valve of a Lingula or Lingu- 

 lella, not sufficient for identification, was observed. 



The Clonograptus bands contain: 



Protospongia sp. p 



Dictyonema flabelliforme Eichwald var. acadicum Matthew r 



