262 



5. "The Lower Sandstones or Subdivision E." 



Fourteen species of fossils were collected by Dr. Dawson in these 

 dejiosits, but three of the former are too imperfect to be determined. 

 Of the eleven species which remain, five, namely, Pleutomaria Skidegor- 

 tensis, Pleuromya subcompressa, var. kevigata, Nemodon Fischeri, Oxyioma 

 mucronata and Lithodomus Maudensis, occur also in the Lower Shales, 

 especially towards or at their basal portion : one is doubtfully identi- 

 fied with the Ammonites Requienianus of d'Orbigny, which is probably a 

 Sphenodiscus : and five (viz., Schloenba^ hia propingua, Cardmn tumidulum, 

 Pecten Carlottensis, Rhynchonella Maudensis, and Discina semipolifa) are 

 here described and figured as apparently new. 



As nearly one-half of the species collected in subdivision E are also 

 found in subdivision C, it is upon the whole most likely that the Lower 

 Shales, the Agglomerates and Lower Sandstones of Dr. Dawson's report, 

 are all merely local and subordinate subdivisions of the same formation, 

 and that the three together represent the lower half of the Middle 

 Cretaceous at this particular locality. It is to be noted, however, that 

 the two Ammonites which occur in the Lower Sandstones are quite 

 different from any of the species found in the Lower Shales. 



ADDENDUM. 



Trigonia intermedia, Fahrenkohl. 



Lyrindon i ntrr medium, FahYenkoU. — 1841. " Ub. einige Fossilien der mos- 



kausch u. kalug. Gouv. voy., 

 Bull de Mosc." Vol. iv. p. 796, 

 pi. 19, fig. 2. 

 —1853. Bull de Mosc, Vol. 1, p. 127. 



(En partie). PaMont. de Russia, 



&c., p.460. 



— 18G7. Lethaea Rossica, Vol- 2. Sect. 1, 



p. 601, pi. 24, figs. 13 a and h. 



—1878. Geol. Surv. Can., Rep. Progr. 



187(i-77, pp. 154 and 155. 

 —1884. This Volume, p. 231, pi. 31, figs. 

 1 and la. 



Lyrodon clavellalua, G. de Fischer. 

 Trigonia clavellata, d'Orbigny. 



Trigonia intermedia, Eichwald. 



Trigonia Daimoni, Whiteaves. 



" " Whiteaves. 



Since the third sheet of the present rej^ort was issued, the writer has 

 ascertained that the Trigonia Dawsoni is almost certainly identical with 

 the above named Russian Neocomian species. 



