THE TERTIARY FORMATION. 9 



discoveries in the anatomy and habits of these animals, and describes seventeen species 

 of Cypris, nearly all of which are new, also three Cytheres (two of them new), and a 

 new genus {Paradoxostoma), from the coast of Madeira, differing from Cythere^ in 

 having its masticatory organs blended together in a conical mass. Lastly he notices 

 a new species oi Asteroj^e {^^Cyjmdina). 



Including the new generic divisions estabUshed by Liljeborg and Zenker, together 

 with the sub-genera proposed for the various fossil and recent forms referable to 

 Cythere, the family CyjjridcB will stand thus : 



Fam. — Cyprid^, Dana. 



Sub-family CYPRINiE, Bana. 



Genus Cypris, MdUer. 



Sub-genus Cypeia, Zenker. 



Genus Gyprois, Zenker. -i Probably 



,, NoTODROMAS, Liljeborg. ) the same. 

 ,, Candona, Baird. 



Sub-gen. [?] Cyprideis,- Jones. 

 „ [?] Cypridea,"' Bosquet. 



Sub-family CYTHERIN^, Da?ia. 

 Genus Cythere,'^ Mailer. 

 Sub-genus Cythereis, Jones. 



,, Cytheridea,^ Bosquet. 

 „ Cytherideis, Jones. 

 „ Ba[rdia,6 M'Coy. 

 ,, [?] Cytherella,'' Jones. 

 Genus [?] Paradoxostoma, Fischer. 



I may here mention that Cyprella and Cypridella, of M. De Koninck, probably 

 belong to a different group of the Entomostraca, — that Bosquet's " Cyprellse " of the 

 Cretaceous and Tertiary deposits are true Cypridina, — and that De Koninck's 

 " Cypridina " (of the Carboniferous Limestone) is not the Cypridina of Milne Edwards. 

 In a courteous reply to an inquiry with which I lately troubled M. Milne Edwards, he 

 kindly informed me that the Cypridina described in the ' Hist. Nat. des Crust.' has 

 really the antero-ventral notch so characteristic of the genus. 



1 It resembles in carapace C. variabilis of Baird. 



2 Having lately again endeavoured to obtain clearer anatomical characters from tlie few dried specimens 

 I possess of this form, I find that the upper antennae are plumeless, as well as the lower pair (see fig. 2, 

 p. 16) ; and the fragmentary posterior limbs appear to be referable to more than two pairs of feet. Under 

 these circumstances we have indications of a fresh or brackish water Cythere. (Oct. 1 85 6.) 



3 Proposed by M. Bosquet as a genus for the " Cyprides " of the Wealden and Purbeck deposits 

 (' Descript. Entom. Tert.,' p. 48) ; their thick and often tuberculated valves have some analogy with those 

 of Cyprideis. 



* Zenker observes that Cythere is perhaps divisible into two genera at least, by the distinctive charac- 

 ters of the spermatozoa; but further anatomical research is required on this point. 



5 Proposed as a genus by M. Bosquet. ^ Proposed as a genus by Blr. M'Coy. 



7 This division is more likely to prove to be a true "genus," when the recent animal is examined, 

 than either of the other fossil forms here indicated as sub-genera ; for it presents a wider departure from 

 the type of carapace of Cythere than any of the others, and intermediate forms appear to be wanting : in its 

 system of " lucid spots " also it difiers from Cythere ; approaching Cypridina in this respect. 



2 



