S78 CONTRIBUTIONS TO CANADIAN PALAEONTOLOGY. 



SCALARIPORA CANADENSIS. (N. Sp.) 



Plate 48, figs. 10, 10a and 106. 



Zoarium consisting of stems that are triangular and almost equilateral in 

 transverse section, the broadest of the three faces having a maximum 

 diameter of about 7'5 mm., and the narrowest of 6-5 mm. Faces 

 shallowly concave or nearly flat : angles acute, forming three sharp, 

 prominent, and nearly straight but rather irregular, longitudinal ridges. 

 Transverse ridges distant, nearly as far apart as the faces are broad, not 

 continuous in either of the two fragments examined, developed (or 

 present) on two of the faces in the longer of these fragments, and on 

 onlv one face in the shorter. Whole surface celluliferous, apertures 

 averaging from about 0-16 mm. to 0-2.5 mm. in diameter, usually rather 

 more than their own diameter apart, or about equal to it in distance, 

 aubciroular, with a slightly elevated annular peristome and arranged 

 obscurely in more or less regular diagonal rows, seven or eight in three 

 mm. Internal structure not observed. 



Thedford, G. Kernahan, 1895 : two specimens, one seventeen millimetres 

 in length and showing two transverse ridges and a partially developed 

 intermediate one ; the other a little more than ten mm. in length and 

 showing only one transverse ridge. Both of these fragments are now in 

 the United States National Museum, and are No. 26, .544 of its Catalogue 

 of Invertebrate Fossils. They were first referred to the genus Scalaripora 

 by Mr. Schuchert, and seem to the writer to differ from S. separata, 

 Ulrich, from the Hamilton formation at Thunder Bay, Michigan,* to 

 which they seem to be most nearly related, by the much greater size of 

 the branches, and apparently also by the irregularity and want of 

 continuity of the transverse ridges. 



Strbblotrypa Hamiltonensis, Nicholson. (Sp.) 



Ccriopora (? ) Hamiltonensis^ Nicholson. 1874. Geol. Mag., N.S., vol. I., p. 161 ; and 



Rep. Pal. Prov. Ontario, p. 97, fig. 33. 

 AcanthocUhta Hamiltonense, Hall. 1887. Pal. N. York, vol. VI., p. 191, pi. 56, figs. 



18-26. 

 Rhombo2Mra Hamilionensis, Nicholson. 1889. In Nicholson and Lyddeker's Man. Pa- 



lieont., vol. I., p. 610, fig. 455 B ; and fig. 478 on p. 632. 

 Strchloirypa Namiltonensis, Ulrich. 1890. Geol. Surv. Illinois, vol. VIII. , p. 648. 



A common species in the neighbourhood of Thedford. 

 Fenestella Nicholsoni. (Nom. prov.) 



Fenestella crihrosa, Nicholson. 1874. Rep. Pal. Prov. Ontario, p. 106, figs. 43, a, h. 

 But probably not F. crihrosa, Hall, 1852, (Pal. N. York, vol. XL, p. 

 166, ])]. 40 D, figs. 3, i(, b,) — which is from the Niagara limestone. 



* Geological Survey of Illinois, vol. VIII., 1890, p. 507, pi. 43, fig. 3. 



