90 CANADIAN MICRO-PALEONTOLOGY. 



tral edge of both valves (figs. 1 h and 3 b is inturned ; but the right 

 overlapping valve (fig. 3 b) has a roundl}^ overturned edge; and the 

 left or overlapped valve has a sharply inturned fiat edge (figs. 1 h and 

 4), against which the opposite edge rested when the carapace was 

 closed. Compare figs. 1 6, 2 b, 4 c, and 7, in pi. vi, * Ann. Mag. Nat. 

 Hist.' ser. 2, vol. XVII, 1856. Inside the lip of the left valve is orna- 

 mented with delicate minute dentilures and striae (fig. 5), as in other 

 instances (see figs. 4 6, 5 6, of the same pi. vi, 1856). 



These valves approach in outline those of Leperditia Tyraica, 

 Schmidt, M^m. Acad. Imp. Sci. St. P^tersbourg, Ser. 7, vol. XXI, 

 No. 2, p. 13, figs. 10 and 11 ; but they are less angular at the ends of 

 the hinge, are without marginal ledges, and are quite smooth, without 

 eye-spot. These specimens are from Jupiter Eiver, Anticosti (collected 

 by Prof. Macoun in 1883), on seven small slabs of compact grey lime- 

 stone, probably composed of small organisms and fragmentf^ of larger 

 forms ; weathering light brown. They belong to the " Division No. 

 2 " of Billings's " Anticosti Group," and are at about the horizon of the 

 Clinton Formation of New York and Ontario. 



This distinct species I propose to name after the eminent Director of 

 the Geological Survey of Canada, A. E. C. Selwyn, C.M.G., F.E.S., &c., 

 under whose auspices this memoir has been undertaken. 



Besides this addition to the Silurian fauna of Anticosti, we must re- 

 member the SIX Beyrichian forms shown in plate xi, and the nine other 

 Ostracoda described and figured in the Quart. Jour. Geol. Soc, vol. 

 XLYI, 1890, pp. 545-550. 



C. FKOM THE DEVONIAN EOCKS. 



Of the Devonian species here described some are from Thedford, 

 Ontario, namely, the specimens represented by figs. 10-13 of pi. xi. 

 Although already referred to in the Quart. Journ. Geol. Soc, these 

 have not hitherto been sufiiciently described and figured. 



Of the others (the original of figs. 14-16, pi. xi) were collected 

 by Mr. McConnell on the Hay Eivei", which runs into Great Slave 

 Lake, and the rest by Mr. Tyrrell at two different localities on Lake 

 Winnipegosis. 



Primitiopsis punctulifera, figs. 10 and 11, is known only in the Hamil- 

 ton group, but the genusis also known in the Upper Silurian of Europe. 



Of the other genera, KirHya ranges from the Silurian to the Carbo- 

 niferous; Ulrichia is also Silurian; Primitia ranges from the Cambro- 

 Silurian to the Carboniferous ; Aparchites, Isochilina, Elpe and Leper- 

 ditia are Cambro-Silurian and Silurian also. 



