64 



to two lines in diameter, Septa represented by numerous (about forty) vertical strife. Mural 

 pores generally in. two or three rows on each of the prismatic faces of the corallites, sometimes 

 in one row, sometimes in several, distant from one another vertically from half a line to over 

 one line. Tabulae exceedingly convex and gibbous, usually with two, three, or four vesicular 

 swellings round their margins, distant from one another from half a line to a line and a half. 

 Locality and Formation. This fine species is of not uncommon occurrence at various local- 

 ities in the Corniferous Limestone of Western Ontario. Amongst localities where it has been 

 observed, may be mentioned Port Colborne ; Lot 6, Con. 1, Wainfleet ; Oxford, near Wood- 

 stock, Ridgeway and Hagersville. It has also been recorded from the Devonian rocks of 

 Michigan, and Preston County, Virginia; 



CHAPTER III. 



BRACHIOPODA OF THE CORNIFEROUS AND HAMILTON FORMATIONS. 



The number of Brackiopoda in the Devonian Rocks of Western Ontario is very consider- 

 able, but good specimens are not obtainable in many parts of the Corniferous Limestone, and 

 our collection of these fossils is not so complete as that of the corals. For this reason, I have, 

 in treating of this group of fossils, availed myself largely of the published papers on this sub- 

 ject by Mr. Billings (Canadian Journ., New Series. Vols. v. and vi.), and also of Prof. Hall's 

 magnificent work on the Brackiopoda of the Devonian Formation of the State of New York 

 (Pal. N. Y. Vol. iv). More especially our specimens, except in a few instances, do not exhi- 

 bit the internal characters of the valves, so important in this class of fossils , and these I have 

 generally quoted at length, for the benefit of Canadian students, from the works of one or 

 other of the above mentioned eminent palaeontologists. 



Altogether, I have identified about forty-three species of Brachiopods from the Devonian 

 of Ontario, belonging to the following genera: Strophomena (seven species), Streptorhynchus 

 (one species) Orthis (two species), ,Chonetcs (seven species), Productella (one species), Spin/era 

 (five species), Cyrtina (one species), Atrypa (two species), Athyris (two species), Leiorhyn- 

 chus (two species), Spirigera (three species), Retzia (one species), Amphigenia (one species), 

 Ccelospira (one species), Centronella (two species), Lingula (two species), Pholidops (one spe- 

 cies), and Crania (one species). 



Of the above, a few species (such as Sirophomena rhomboidalis, Spirifera mucronata, and 

 Atrypa reticularis) are well known European forms; and others are nearly allied to European, 

 species, if not quite identical with them ; but the greater number are peculiar to the American 

 Continent. 



76. STROPHOMENA PERPLANA (Conrad). 



Sirophomena perplana (Conrad), Journ. Acad. Nat. Science, Vol. viii. p. 257. PL XIV, 

 fig. 11. 



Strophomena pluristriata (Conrad,) op. cit., p. 259. 



Strophomena delthyris (Conrad), op. cit., p. 258. 



Strophomena crenistria (Hall), Report Fourth Geological District. New York, p. 171, 

 fig- 4. 



Strophomena fragilis (Hall), Tenth Report on the State Cabinet, p. 143 ; and Rep. Geol. 

 Survey of Iowa, p. 496. PL iii. fig. G a, 6 c. 



Strophomena perplana (Billings), Journ. Can. Institute, New Series, Vol. VI. p. 343. 



Strophodonta perpluna ; (Hall), Pal. N Y., Vol. iv. p. 98. Pis. XL XII. XVIII. and 

 XIX. 



Form semi-elliptical or semi-circular ; the width exceeding the length, though not greatly- 

 Valves flattened, or slightly concavo-convex, regularly rounded in front. Hinge-line straight, 

 as long as, or longer than, the greatest width of the shell, which is sometimes extended to- 

 wards the cardinal angles or almost auriculate. Ventral valve slightly convex, with its 

 greatest convexity at about one-third from the beak ; the dorsal valve gently concave or 



