2^ 



FossUiferous RocJcs in Nova Scotia. 193 



The height of the tooth is 2j lines, and almost equal to the 

 breadth. The lateral denticles half as broad as high, flattened 

 and serrated, especially at the outer margin and near the base ; 

 cross section of the denticles rhomboid. They diverge at an angle 

 of 35^ to 40<^. The central denticle is minute and conical. 2. 

 Ctenoptychius, a small species indicated by a tooth with eight 

 denticles. The specimen is an imperfect impression. 



Of ganoid fishes there are numerous scales of small species be- 

 longing to Palaeoniscus or allied genera, broad flat scales punc- 

 tured and lined after the manner of Osteoplax of McCoy, and 

 others marked with fine wavy lines, as in Holoptychius or Rhizo- 

 dus. There is also a curved conical tooth belonging to one of 

 these latter fishes, and difl'ering from others that I have seen in 

 having the concave side marked with fine spiral ridges nearly to 

 the point. There are also certain flat sabre-like spines of small 

 size, but much resembling in form those of the Devonian Macli- 

 ceracanthi. 



The above are chiefly in the coals and shales overlying or near 

 the great conglomerate. In the lower measures at McLellan's 

 Brook, are bivalve shells of thatmodiok or unio-like form, charac- 

 teristic of the fresh and brackish water portion of the coal mea- 

 sures, and which I have elsewhere designated by the generic 

 name Naiadites. They are all thin, inequilateral, toothless, and 

 marked by concentric lines of growth. A new species in the 

 present collection, iV, ohtusa^ is characterized by the broad and 

 truncate outline of the anterior extremity, giving it a somewhat 

 quadrilateral form. 



The Spirorhis found abundantly in several of the beds noticed, 

 is the ordinary Sp. {Microconchus) carhonarlus common to the 

 American and European coal fields.] 



ARTICLE XLI. — On new Localities of FossUiferous Silu- 

 rian Rocks in Eastern JSfova Scotia, By Rev. D. Honeyman. 



(Read before the Natural History Society.) 



This subject has already been very fully discussed in Dr, 

 Dawson's Acadian Geology and in his recent paper read to this 

 Society, with Professor Hall's elaborate and valuable Memoir on 

 th« Fossils of Arisaig. 



