CYPRELLA. ' 41 



the reader), and the apiculate and indented hinder margin (downwards in fig. 3 a, b), are 

 very characteristic. 



Fig. 12 is a grey valve (showing reticulate sculpture under the microscope, 12 3) in grey 

 limestone from Cork (Mr. J. Wright, F.G.S.). It seems to be rounded in front, but 

 is really imbedded in the matrix ; it has a low tubercle, and a strong, broad, transverse 

 furrow across the surface, the hinder moiety of the valve being very convex. 



Fig. 13 is a larger valve, grey, with a suborbicular outline; from the grey limestone 

 of Settle; collected by Mr. J. H. Burrow, M.A., who has enriched our list with many 

 Carboniferous species. 



Fig. 17, a grey shell in grey limestone, is more ovate than either of the foregoing, 

 being narrower in vertical diameter ; perhaps a male. It was collected, with a few others, 

 at Little Island, Cork, by Mr. J. Wright, F.G.S., who has been so successful in his search 

 in the Carboniferous Limestone of Cork, Ireland. 



We have also seen a specimen of this species in Mr. W. Grossart's collection from 

 the Carboniferous Limestone of Bathgate, Linlithgowshire. 



Our specimens are much less depressed at the nuchal furrow than Prof. De Koninck's 

 original seems to have been ; but evidently that is a variable feature. 



Cyprella annulata is said to be very rare at Vise, Belgium (De Koninck), and in French 

 Hainault (Dupont). 



We now return to some forms closely related to Cypridina, and well known in the 

 recent state, namely, Bradycinetus and Fhilomedes. Of the former we have certainly a 

 good representative in the Carboniferous Formation at Carluke, Scotland ; of the latter a 

 less decided, but very probable, representative has been sent to us from the Carboni- 

 ferous Limestone of Cork, Ireland. After having treated of some other fossil forms, 

 which, however, have no closely allied existing representative, but are evidently 

 Cypridinads {Entomoconchus and Offa), we shall treat of some fossil forms of Polycope 

 and Cytherella, and then take up some extinct Entomostraca {Entomis), whose relationship 

 with the Ostracoda is obscure, and in which the absence of the anterior notch and the 

 presence of a strong nuchal furrow are distinguishing features. 



