PRELIMINARY OBSERVATIONS. 9 
the two last-named palzontologists give us descriptions, lists, and beautiful illustrations 
~of all the Russian Silurian Brachiopoda known at the time of the publication of their 
labours. Count Keyserling, in a subsequent work, ‘Reise in das Petschora-Land,’ 1846, 
adds some figures and descriptions of Russian Brachiopoda to those already made known 
in 1845. 
Dr. S. Kurorea has likewise contributed to our knowledge of Russian Silurian 
Brachiopoda, and his memoirs in the ‘ Dritter Beitrag zur Palaiontologie Russlands’ for 
1846, and his paper in the ‘ Verhandlungen der Kaiserlichen Mineralogischen Gesellschaft, 
fir 1847,’ may be particularly noticed, as it contains admirable figures of some new 
genera, and especially of Siphonotreta, Obolus, and Aulonotreta. 
Herr Frepericn Scumipt’s excellent work, “ Untersuchungen tiber die Silurische 
Formation von Ehstland, Nord-Livland, und Oesel,” published in the ‘ Archiv fiir die 
Naturkunde Liv-,’ Ehst- und Kurlands, 1st series, vol. 11, Dorpat, p. 1—248, 1858, con- 
tains lists and descriptions of many Silurian Brachiopoda, of which a certain number 
appear to be identical with those found in Sweden and Great Britain. 
Herr M. von Grtinewatpt has also published descriptions and figures of Russian 
Silurian Brachiopoda in a memoir, “ Ueber die Verst. der Silurischen Kalksteme von 
Bogosslowsk,” &c., in the 7th vol. ‘Des Mémoires des Savants Etrangers de St.-Peters- 
bourg, 1854, and in his memoir, ‘Beitrige zur Kenntniss der Sediment. Gebirgs- — 
formationen in den Berghauptmannschaften Ekatermburg, Slataust und Kushvina,’ 4to, 
1860. 
K. E. v. Barr and Gr. v. Hetmursen’s ‘Beitrage zur Kenntniss des Russ. Reichs und 
der angranzenden Lander Asiens’ contains several articles by D’E1cuwap on Brachiopoda. 
This work has continued to appear during the last twenty-five years. Silurian Brachiopoda 
have also been described in the ‘ Bulletin de la Société des Naturalistes de Moscou,’ in the 
Transactions of the Academy of Sciences of St. Petersburg, and in the ‘ Verhandlungen 
der Kaiserl. Min. Gesellschaft zu St.-Petersburg’ for 1842—1863, &c. 
MaximiusaAn Herzoc von Leucutensere, ‘ Beschreibung einiger Thierreste der 
Urwelt aus den Silurischen Kalkschichten von Sarskoje.’ Selo, 1843. 
BELGIUM. 
But little has been published on Belgian Silurian Brachiopoda; we may, however, 
mention the following papers : 
2 
