GLASS-SPONGE COLONIES OF THE DEVONIAN 27 



market and it was thrown out on the spoil bank. The discarded 

 blocks came to the attention of the state's geologists and a carload 

 of the layer was specially quarried for them. One slab of this 

 layer, 8'X4', now exposed in the State Museum, carries about 250 

 sponges lying as they were left, knocked over on their sides by some 

 heavy tide. The carload of sponges contained probably not less 

 than 5,000 individuals. The layer carrying them extended over the 

 full face of the quarry, 120 feet, and indefinitely inward. The 

 census of the colony cannot be estimated except in very large figures 

 of tens of thousands. 



4. The Irish Hill Colony, near Bath. — ^This is known only by 

 the multitude of specimens of H. botroedema found loose in the 

 soil at this place. 



5. The Haiti Colony at Wetlsvilte, Allegany County. — Here the 

 horizon is high in the formation and the species is Thysanodictya 

 Edwin-Hatli H., of which several hundred specimens were found 

 by the late E. B. Hall, of Wellsville. 



PREVIOUS HISTORY OF THE DICTYOSPONGIDA 



Limiting the term to the characteristic expressions of the 

 Devonian and Mississippian, they have little record of previous 

 history; there is a single doubtful specimen from the mud beds of 

 the Hamilton shales {Clathrospongia ? hamiltonensis Hall) and some 

 hexactin patches in the black Marcellus shale, D. ? marcettia Clarke. 

 Fragments of like type, but heretofore unrecorded, have been 

 found in the Rochester shale of New York. In this statement we 

 are eliminating from the group the Cyathospongia forms of the 

 Utica shale, the Levis beds of Little Metis (Ordovician) , and the 

 extensive assemblage of similar hexactinellids in the Cambrian, 

 especially those found by Walcott but not yet described. It is 

 proper to exclude these even though they may have full ordinal 

 relation with the Devonian species, because of the vast vacant 

 interval of time between the earlier and later records. There 

 were species of these sponges in the upper beds of the Portage 

 group (three of Hydnoceras, one of Prismodictya, one of Dictyospon- 

 gia, and one of Clepsydrospongia) , but they must be regarded as 



