■280 CONTRIBUTIONS TO CANADIAN PALAEONTOLOGY. 



Dawson Bay, Lake Winnipegosis, on the south-east side, at Whiteaves 

 Point (two specimens) and on the west side, at the south end of Rowan 

 Ishind, also on the east side of Lake Winnipegosis at a small island oppo- 

 site Birch Island, three specimens ; J. B. Tyrrell and T>. B. Dowling, 

 1889. 



The specimens from these localities agree fairly well with Hall's figures 

 of F. disjiiiridfi, but their identication with that species is doubtful, owing 

 to the contradictory nature of the measurements given in its description. 

 They diti'er from the specimens here referred to F. vera, in their straggling 

 mode of growth, striated noncelluliferous surface, large oblong fenest- 

 rules, and in their more slender branches and dissepiments. 



(S-) PoLYPORA (POROSA ? var.) Manitobensis. 



Plate 36, fig. 5. 



Cfr. Fenestdla porosa. Hall. 1881. Trans. Albany Inst., vol. X, abstract, p. 26. 



Frneslella {Po/yjiora) porom, Hall. 1883. Rep. St. Geol. for 1882, Exjjl., pi. 31, 



figs. 1-U. 



1887. Pal. St. N. York, vol. VI, p. 163, pi. 

 .xx.wiii, figs. 1-6. 



Zoai'ium infundibuliform, rather widely expanding, irregularly and 

 shallowly undulated. Branches slender, usually zigzag when the fenes- 

 trules are alternate, but occasionally straight where they are opposite and 

 appeai-ing externally, on the noncelluliferous side, as smooth (?) slightly 

 angular longitudinal ridges, which are a little broader than the trans\'erse 

 noncelluliferous dissepiments. Fene.8trulcs lai'ge, a little longer than 

 wide, elliptical or approaching to hexagonal in outline and averaging about 

 ■8 mm. in length and '6 mm. in width. In a distance of six millimetres 

 there ai-e four fenestrules as measured longitudinally, and six as measured 

 transversely. Cell apertures disposed in from two to four alternating lon- 

 gitudinal rows, about four of these apertures in each row to the length of 

 a fenestrule. 



Monroe Point, Lake Manitoba, J. B. Tyrrell and J. F. Whiteaves, 

 1888 four specimens. Dawson Bay, Lake Winnipegosis, on three small 

 islands, two on the south-east side and the other in the southern portion 

 of the bay, also on its eastern shore, at the second point north of the 

 mouth of the Red Deer River, J. B. Tyrrell and D. B. Dowling, 1889 : a 

 few specimens from each of these localities. 



In each of these it is only the noncelluliferous outer surface that is 

 exposed, the characters of the zocrcia having lichen ascertained by scraping 

 down small portions of the branches. The close affinity of these speci- 

 mens to the /'. poro.sii of Hall was suggested to the writer by Mr. Ulrich. 



