146 DrCTYOSPONGID^. 



Observations. It may be possible that in this species we have not a true 

 thin-walled Dictyosponge, as its form, relatively small aperture, and the, radial 

 canals upon its surface all suggest some of the thicker-walled sponges, such 

 for example, as those of the genus Pachytrichisma, one of the dictyonine 

 family, Ventriculitid^. (For comparison see Zittel, Handhuchder Palaeon- 

 tologie, vol. 1, p. 177, P. (Jarteri, Zittel, fig. 92.) Nevertheless, such positive 

 evidence as here presented, affords no good reason for excluding this peculiar 

 genus, Aglithodictya, from the Dictyospongid^. 



Locality. In the sandstones of the Chemung group, near Lawrenceville, 

 Tioga county, Pennsylvania. 



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