NEW AMERICAN PALEOZOIC OSTRACODA. 



PRELIMINARY REVISION OF THE BEYRICIIIIDJE, WITH 

 DESCRIPTIONS OF NEW GENERA/' 



By Edward 0. Uleich, 

 Geologist, U. 8. Geological Survey, 



AND 



Ray S. Bassler, 



Curator, Division of Invertebrate Paleontology. 



INTRODUCTION. 



As defined in modern text-books, the Paleozoic family of Ostra- 

 coda, Beyrichiiclay embraces a large and constantly growing assem- 

 blage of genera and species. The unwieldiness of the typical genus 

 Beyrichia became apparent some forty years ago, when T. Rupert 

 Jones, the well-known and highly conservative English authority. 

 and H. B. Holl tirst suggested the separation of the " siniplices " as a 

 distinct generic group under the name Primitia? At a later date 

 these authors proposed the separation of the less sharply defined 

 " Corrugatse " group, typified by Beyrichia wilckensiana, under the 

 name Klmdenia. In the same paper they propose the genus 

 Bolliaf and in the next succeeding number of that periodical two 

 other generic groups are distinguished as Strepula ' and PlacentulaJ 



Working independently, Jones had also instituted the genus Kirk- 

 bya.o for a Permian species thought to have relations to the Bey- 



" For previous articles of this series see Jour. Cincinnati Soc. Nat. Hist., XIX, 

 1900, pp. 179-185, and Proc. U. S. Nat. Mus., XXX, No. 1446, 1906, pp. 149-164, 

 pi. xi. 



» Ann. and Mag. Nat. Hist. (3), XVI, 1865, p. 415. 



In 1855 (Ann. and Mag. Nat. Hist. (2), XVI, p. 85), Jones divided Bey- 

 richia, as then defined by him, into three groups, (1 ) " siniplices," including the 

 forms subsequently referred to Primitia and allied genera; (2) "Corrugatse," 

 with li. tcilekensiana as the type of the group, and (.'!) " Jugosse," including, 

 besides /»'. kloedeni, the type of the genus, also certain Ordovician species subse- 

 quently referred to Tetradella and Ctenobolbina by Ulrich. 



'Ann. and Mag. Nat. Hist. (5), XVII, pp. 347, 362. 



d Idem, p. 300. 



( ' Idem, p. 403. 



' Idem, p. 407. 



t> Trans. Tyneside Nat. Field Club, IV, 1859, pp. 129, 134, 136. 



Proceedings U. S. National Museum, Vol. XXXV— No. 1 646. 



277 



