r HE ANNALS 



AND 



MAGAZINE OF NATURAL HISTORY. 



[SECOND SERIES.] 

 No. 98. FEBRUARY 1856. 



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

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



[With two Plates.] 



[Continued from vol. .\vi. p. 176.] 



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

 have described the little Beyrichia of the Upper and Lower 

 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 t from the palaeozoic rocks of Goth- 

 land were figured and described more than twenty years ago by 

 Hisinger :|:, who recognized their general dissimilarity to the 

 Conchifcra, and referred them to the Entomostracan genus 

 Cythere, which was the only marine bivalved form of the Sub- 

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



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

 Limestone of Toumay, Belgium. 



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

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

 latter. Kloden's Cytherina phaseolus (Verst. ilark Brandenburg, j). 102. 

 pi. 1. fig. 10) appeai-s 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 conesjjond. 



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

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



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

 work on the " Entomostraca," published in 1785, and again in 17!'2, were 

 still the chief sources of information on this subject. 



Ann. &)• Mag. N. Hist. Ser. 2. Vol. xvii. 6 



