174 



former are more full, and the valves themselves proportionately more 

 convex than those of S. Kingii." 



Lept^na unicostata, Meek and Worthen. (Sp.) 



Sirop/iomeMn !)iricostofc(. Meek and Worthen.. 1868. Geol. Surv. Illinois, vol. III., p. 335, 



pi. 4, fig. 11. 

 Whitfield 1882. Gteol. Wisconsin, vol. IV., p. 262, pi. 



12, fig. 14. 

 Xejstfena wmicostoto, Winohell and Schuchert.1893. Lower Silur. Braoh. Minn., p. 411, 



pi. 32, figs. 6-9. 



Lower Fort Garry, T. C. Weston, 1884 : one specimen. 



On Lake Winnipeg a few specimens have been collected at Kinwow 

 Bay by T. C. Weston in 1884 ; at Cat Head by D. B. Dowling and L. 

 M. Lambe in 1890 ; at Inmost or Birch Island by D. B. Dowling and L. 

 M. Lambe in 1890 ; at Clark's Point by D. B. Dowling in 1891 ; on the 

 -west shore north of the Saskatchewan and opposite the north end of 

 Selkirk Island by D. B. Dowling in 1891; and at the First Limestone 

 Point on the west shore north of the Saskatchewan by D. B. Dowling 

 in 1891. 



Keewatin, Limestone Rapids 100 miles up the Nelson River, Dr. R. 

 Bell, 1879 : one ventral valve. 



Plectambonites seeicea, Sowerby. (Sp.) 



Leptcena serirea, Sowerby 1839. In Murchison's Silur. Syst., pi. 19, 



figs. 1 and 2. 



Strophomena sericea, Conrad 1840. Third Ann. Rep. Geol. Surv. N. York, 



p. 201. 



„ „ Emmons 1842. Geol. N. York, Rep. Third District, 



p, 47. 



Zeptcena sericea. Hall 1847. Pal. N. York, vol. I. , pp. , 110 and 287, 



pi. 2lB, fig. 2, and pi. 79, fig. 13. 



1852. Ibidem, vol. II., p. 59, pi. 21, fig. 1. 



,r rr Billings 1856. Canad. Nat. and Geol., vol. I., p. 41, 



fig. 2. 



1863. Geol. Canad., p. 163, fig. 139: and of 



many subsequent writers on U. S. and 

 Canadian fossils. 



Flectambonites sericea, Hall 1892. Pal. N. York, vol. VIII., pt. 1, pi. 15, 



figs. 25-29. 

 ri M Winohell and Schu- 



chert 1893. Lower Silur. Brach. Minn., p. 414, 



pi. 32, figs. 10-12. 



This well known species has been collected at I/Ower Fort Garry by 

 Dr. A. R. C. Selwyn in 1872, and by Mr. Weston in 1884. At Lake 

 Winnipeg it has been collected on Elk Island by T. C. Weston in 1884 ; 

 at Inmost or Birch Island, in Kinwow Bay, by T. C. Weston in 1884, 



