Palceozoic Bivulved Entomostraca. 339 



completeness. Lately Herr G. Eeuter has given, in the 

 Zeitschr. d. d. geol, Ges. vol. xxxvii. 1885, pp. 621 et seq., a 

 sketch of the history of the genus, with elaborate notes on its 

 structural characters, on several of its species, their apparent 

 genetic order, and their distribution in the Upper- Silurian 

 rocks of Scandinavia, as indicated both by the Ostracoda 

 found in the drifted blocks in North Germany and by those 

 known in the parent strata. 



The chief memoirs subsequent to those by Kloden (1834) 

 and Jones (1855) treating of tlie Beyrichian limestones of 

 Scandinavia in the Drift of Northern Europe are : — 



1858. Ferd. Eomer. Neues Jahrb. 1858, p. 270. 



1859. Friedrich Schmidt. Archiv f. d. Naturk. Liv-, 



Ehst- und Kurlands, ser. 1, vol. ii. part 2, 1859, 

 pp. 443, 445, 448, 453, 461-463. 



1861. C. Grewingk. Ibid, part 3, 1861, pp. 571, 660, 



&c. 



1862. Ferd. Eomer. Zeitschr. d. d. geol. Ges. vol. xiv. 



1862, p. 607. 

 1862. E. Boll. Archiv Ver. Fr. Nat. Meklenburg, 16. 



Jahrg. 1862, pp. 114 &c. 

 1869. G. Karsten. Beitr. Landeskund. Herzog. Schleswig 



und Holstein, ser. 1, part 1, 1869, pp. 1 &c. 

 1869. Heidenhain. Zeitschr. d. d. geol. Ges. vol. xxi. 1869, 



pp. 143-182. 

 1874. Feistmantel. Neues Vorkommen nord. Silur. Diluv. 



Lampersdorf, &c. 



1877. A. Krause. Zeitschr, d. d. geol. Ges. vol. xxix. 1877,» 



pp. 33-45 &c. 



1878. K. Haupt. Neues Lausitzisches Magaziu, vol. liv. 



1878, p. 75. 

 1881. W. Dames, Zeitschr. d. d. geol. Ges. vol. xxxiii. 

 1881, pp. 434-441. 



1884. J. Kiesow. Schriften der naturforschenden Gesell- 



schaft in Danzig, new ser. vol. vi. part i, 1884, 

 pp. 205 &c. _ "^^^^^ 



1885. G. Eeuter. Zeitschr. d. d. geol. Ges. vol. xx,,vi : 



1885, pp. 621-681. \$- 



Herr Eeuter, like other observers, has been especially struck 

 with the peculiarity of the extra large lobe present in 

 many individuals among the Silurian Beyrichice towards one 

 end of the ventral region of each valve. In the Proc. Geol. 

 Assoc, Pal. Biv. Entom., 1869, p. 11, its cause was referred 



