186 



HISTORICAL PALAEONTOLOGY. 



latter is a huge May-fly (Haplophlebium Barnesi, fig. 125), with 

 netted wings attaining an expanse of fully seven inches, and 

 therefore much exceeding any existing Ephemerid in point 

 of size. 



The lower groups of the Mollusca are abundantly represented 



Fig. 124. Xylobiiis Sigillarice, a Carboniferous Myriapod. a, A specimen, of the 

 natural size ; 6, Anterior portion of the same, enlarged ; c. Posterior portion, enlarged. 

 From the Coal-uieasures of Nova Scotia. (After Dawson.) 



in the marine strata of the Carboniferous series by Polyzoans 

 and Brachiopods. Amongst the former, although a variety of 



Fig. 125.ffaplophlebium Barnesi, a Carboniferous insect, from the Coal-measures 

 of Nova Scotia. (After Dawson.) 



other types are known, the majority still belong to the old 

 group of the "Lace-corals" (Fenestellida), some of the charac- 

 teristic forms of which are here figured (fig. 126). The graceful 

 netted fronds of Fenestella, Retepora, and Polypora(fig. 126 a) 



