THE ANNALS 



AND 



MAGAZINE OF NATURAL HISTORY, 



[SECOND SERIES.] 

 No. 98. FEBRUARY 1856. 



VIII. — Notes on the Palaeozoic Bivalved Entomostraca. No. III. 

 Some Species of Leperditia. By T. Rupert Jones, F.G.S. 



[With two Plates.] 



[Continued from vol. xvi. p. 176.] 



In Notes I. and II. (^Annals/ August and September 1855) I 

 have described the little Beyrichice of the Upper and Lov^er 

 Silurian rocks, especially of Sweden and Britain ; in this paper 

 I propose to describe other small Bivalved Entomostracan Crus- 

 taceans, larger than the former, and characteristically distinct. 

 These are from the Silurian rocks of Scandinavia, Russia, Arctic 

 America, and England ; except one which is from the Devonian 

 rocks of Normandy *. 



Two little fossil bivalves f from the palaeozoic rocks of Goth- 

 land were figured and described more than twenty years ago by 

 Hisinger J, who recognized their general dissimilarity to the 

 Conchifera, and referred them to the Entomostracan genus 

 CytherCj which was the only marine bivalved form of the Sub- 

 class of the Crustacea at that time known to naturalists §. 



* I have also seen lately a typical Leperditia from the Carboniferous 

 Limestone of Tournay, Belgium. 



t Cytherina Balthica and C. phaseolus. It is only of the former that I 

 can here speak, — as I have not yet obtained any specimen referable to the 

 latter. Kloden's Cytherina phaseolus (Verst. Mark Brandenburg, p. 102. 

 pi. 1. fig. 10) appears to be a distinct form, of great interest. M'Coy has 

 referred to C. phaseolus some Irish Silurian specimens ; but Mr. Salter 

 assures me that they do not correspond. 



X In his ' Anteckningar i Physik och Geognosi under resor uti Sverige 

 och Norige ;' and also in his ' Lethrea Suecica.' 



§ O. F. Miiller's Notes in the ' Philos. Trans.' 1771, and his elaborate 

 work on the " Entomostraca," pubhshed in 1785, and again in 17^2, were 

 still the chief sources of information on this subject. 



Ann. §• Maff. N. Hist. Ser. 2. Vol. xvii. 6 



