314 Prof. H. A. Nicholson on some new or 



described and figured this species (Mon. Brit. Strom, p. 186, 

 pi. X. figs. 5-7, and pi. xxiii. figs. 4-7) ; and the Canadian 

 specimens, from their poor preservation, necessarily afford 

 nothing further to add to our information regarding the 

 species. 



Formation and Locality. The specimens which I am dis- 

 posed to refer here are from the Devonian rocks of Lake 

 Winnipegosis (Islands 50 and b^^ Dawson Bay). Another 

 specimen, from Snake Island, may perhaps be also referable to 

 this species. 



Stromatoporaj sp. 

 (Cf. Stromatopora Hupschii, Barg., sp.) 



Two of the specimens collected by the officers of the Geolo- 

 gical Survey from the Devonian rocks of Lake Winnipegosis 

 belong to a species of Stromatopora in many respects similar 

 to 8. liiipschii^ Barg. Structurally these specimens agree 

 with the latter common European and British type, and differ 

 from S. hiic/ieh'enst's, Barg., in their coarse skeleton-fibre, the 

 lax reticulation of tlie skeleton, and the loose spreading form 

 of the astrorhizfB. The internal structure of these specimens 

 is, however, very poorly preserved, and it would be rash to 

 refer them unreservedly to S. Hilpschn. 



Formation and Locality. Dolomitic limestones of Devonian 

 age. Lake Winnipegosis. 



Stromatopora Carterij Nich. (PI. IX. figs. 5 and 6.) 



Stromatopora Carteri, Nicholson, Mon. Brit. Strom, p. 174, pi. i. figs. 6 

 and 7, and pi. xxiii. figs. 1 and 3 (1886 and 1891). 



The ccenosteum in this species is massive and irregular in 

 shape and is composed of gently curved latilaminas, while the 

 upper surface is without '' mamelons," and does not exhibit 

 clearly developed astrorhizse. The skeleton-fibre is thick and 

 coarsely porous. Vertical sections (PI. IX. fig. 6) show that 

 each latilamina is composed of stout radial pillars, somewhat 

 flexuous, and running continuously from the bottom to the top 

 of each latilamina, and united into an open network by a few 

 irregular connecting-processes. The zooidal tubes are fur- 

 nished with " tabulae," and are separated by the radial pillars, 

 about seven of which, with their intervening tubes, occupy a 

 space of 2 niillim. measured transversely. Tangential sections 

 (PI. IX. fig. 5) show a loose reticulate skeleton, perforated 

 by the transversely divided zooidal tubes, which may be 



