V. NOTES ON DR. AMI'S PAPER ON DICTYOXEMA SLATES OF 

 ANGUS BROOK, NEW CANAAN, AND KEXTVILLE, N. S. 

 BY HENRY S. POOLE, F. 0. S., F. R. S. C., ETC. 



(Read 10th February, 1902.) 



When handed Dr. Ami's paper to read at this meeting, I was 

 requested to make some remarks on it. I comply, but only do 

 so with the understanding that I can speak with no authority, 

 nor am I able to properly discuss it. 



It may be of interest to some present to know that the fossil 

 in question, Dictyonema, is classed with the curious fossil forms, 

 Graptolites, and the modern Sertularia among the order of 

 Hydrozoa. These beautiful zoophites are like branching plants 

 and are found on temperate coasts. They have two rows of cells 

 on the horny branches. 



The Dictyonema also reminds one of the coral Fenestella 

 which occurs in the limestones at Windsor and Brookfield in 

 lower carboniferous rocks ; but the branches of Fenestella which 

 frequently biforate are connected by narrow bands, with charac- 

 teristic round cellules on a calcareous frond. The skeleton of 

 Dictyonema is striated, serrated and horny. The animals of 

 this class are jelly-like, radially symmetrical, living in colonies, 

 and building up for the common good these horny structures 

 which have been preserved as fossils while all trace of the 

 animal has disappeared. The allies of the Dictyonema, the 

 Graptolites, reached their maximum in Silurian times, and dis- 

 appeared with that age after evolving many varieties of form 

 and habit. 



Sir A. Geikie speaks of Dictyonema as a characteristic fossil 

 of the primordial zone in Scandinavia, where it is associated 

 with allied but doubtful forms. In Canada it also occurs at 

 Point Levis and other places, with graptolites. 



(451) 



