78 



ter of the aperture of the largest specimen collected, three lines ; height 

 of the apex, two lines. 



Occurs at Topsail Head, Conception Bay. 



Species resembling this have been heretofore referred to Caimlus^Metop- 

 toma, &c., to \yhich, however, they do not belong. Tor the present I 

 propose to refer those with a strongly corrugated surface to StenotJieca^ 

 and the others with a smoother surface to Scenella- 



3.-0/1 the Genus Stricklandinia, ivith descriptions of the Canadian species. 

 Genus Stricklandinia. (BilHngs.) 1859. 



Stricklandia. (Billings.) Canadiaa Naturalist and Geologist, vol. 4, p. 132, April, 1859. 

 Stricklandinia. (Id. ) Op. cit. Vol. 8, p. 370, October, 1863. 



(Ralph Tate.) Appendix to Woodward's Manual of Mollusca, p. 59, 1868 „ 



(Davidson.) British Brachiopoda, vol. 3, p. 157, 1867. 



(Hall.) Palasontology of N.Y., vol. 4, p. 369, 1867. 



Generic Characters. Shell usually large, elongate-oval, transversely- 

 oval, or circular : in some species with a straight hinge-line, more or less, 

 extended ; valves nearly equal, varying from depressed convex to strongly 

 convex ; a short mesial septum in the interior of the ventral valve, sup- 

 porting a small triangular chamber beneath the beak as in Pentamerus; 

 in the dorsal valve two very short or rudimeiitary socket plates, which in 

 some species bear prolonged calcified processes for the support of the cir-« 

 rated arms. Both valves with an area, that of the ventral valve the 

 largest ; the dorsal area sometimes incurved over the ventral and conceal- 

 ing it wholly, or in part. 



No muscular impressions have as yet been clearly observed in the ven- 

 tral valve, but in the dorsal there are two oblong or sub-ovate scars a little 

 below the beak, one on each side of the median line. These were first 

 made known by Mr. Davidson and figured in his " British Brachiopoda, 

 vol. 3, plates 19 and 20, and they are also seen in S. Canadensis. The 

 surface is usually coarsely and rather irregularly covered with radiating 

 ridges ; sometimes nearly smooth. 



All the English species of Stricklandinia were formerly included in 

 the genus Pentamerus. The first intimation of a distinction between 

 them and the typical forms of the latter genus was pubUshed in Mr. 

 Davidson's " General Introduction," 1854, p. 98. The characters oa 

 which this distinction was founded were discovered by the late J. W. 

 Salter, Esq., Pal^Bntologist of the Geological Survey of Great Britain. In 

 his account of the internal characters of Pentamerus, Mr. Davidson 



• 



says : — 



" The position of the mesial plate and V shaped process in the dental valve has been 

 clearly shown, both by Baron V. Buch and Professor King, to be the equi valent of the me- 



