I. Chlupáč

The Lower Cambrian fauna of the Paseky Shale (Brdy Mts., central Bohemia) consists of three non-trilobitc arthropods: the markedly dominant Kodymirus vagcns Chlupáč et Havlíček, 1965, interpreted as the earliest representative of the class Eurypterida with some superficial resemblance with aglaspidids, the newly described and probably related Kockurus grandis n. gen. et sp., and the crustacean Vladicaris subtilis n. gen. et sp. This low diversity and endemic fauna inhabiited a special non-marine or restricted marine, probably brackish and lagoonal environment, exceptional for lhe Cambrian Period.

Representatives of the family Pterygotidae Clarke et Ruedemann, 1912 from the Ludlovian, Přídolian and Lochkovian strata of the Barrandian area, central Bohemia (Czech Republic) are reviewed and discussed: Acutiramus bohemicus (Barrande, 1872), A.  perneri sp. n, A. nobilis (Barrande, 1872), Pterygotus barrandei Semper 1898, P. kopaninensis Barrande, 1872 and doubtful species P. mediocris Barrande, 1872 and P. blahai Semper 1898. Pterygotids show their maximum development in strata of Přídolian age and they tend to be concentrated in offshore dark platy limestone facies with anoxic bottom influences. They are constituents of marine faunae and exhibit the same environmental dependence as the coeval phyllocarid crustaceans of the fam. Ceratiocarididae.