358 



MR. G. S. BRADY'S MONOGRAPH OF 



Norman, and Robertson ; and our knowledge of them may be considered tolerably 

 good. 



3. British type, comprising species diffused pretty evenly over the seas of Great Britain 



and Ireland. 



4. Atlantic type, referring to those which attain their greatest luxuriance on the 



south and south-western shores of England and Ireland. 



5. Mediterranean type, including species which attain their maximum of development 



in the Mediterranean. These are very imperfectly known, chiefly from specimens 

 described by Dr. Baird and myself, and from some further dredgings which have 

 been placed in my hands by M. de Polin of Pauillac, and which I have already 

 • partially described in a French publication, ' Les Ponds de la Mer.' 



It will be seen that the above is a very imperfect attempt at typical distribution ; but 

 such as it is, it seems to me to be better than none at all, and to add considerably to the 

 interest attaching to the various species. 



Eor the details of geological distribution, I am indebted much to the works of Prof. 

 T. Rupert Jones, Bosquet, G. O. Sars, Beuss, Speyer, and Egger, but chiefly to the large 

 collections of posttertiary species made, in anticipation of a monograph of the subject, 

 by Messrs. Crosskey and Robertson, of Glasgow. 



The following classified Table of the Ostracoda is compiled from various authors, and 

 exhibits the present state of our knowledge of the subject. Those marked with an 

 asterisk are known only in the fossil state ; whether a right situation is here assigned 

 them must be doubtful : — 



Class CRUSTACEA. 

 Subclass ENTOMOSTRACA. 

 Order GNATHOSTOMATA. 

 Legion Lophyropoda. 

 Tribe Ostracoda. 



Section Podocopa. 



Family 1. CypRiDiE. 



Genns Cypris. 



Chlamydotheca (?) . 



Cypridopsis. 



Paracypris. 



Aglaiaf. 



Notodromas. 



Candona. 



Pontocypris. 



Argilloecia. 



Bairdia. 



Macrocypris. 



Family 2. Cytherid^,. 



Genus Cy there. 



Limuocy there. 

 Cytheridea. 

 Eucy there. 



Genus Ilyobates. 



Loxoconcha. 



Xestoleberis. 



Cytherura. 



Cytheropteron. 



By thocy there. 



Pseudocythere. 



Cytherideis. 



Sclerochilus. 



Paradoxostoma. 



Section Myodocopa. 



Family 3. Cypridinid^. 



Genus Cypridina. 

 Asterope (?) . 

 Bradycinetus. 

 Eurypylus f . 

 Philomedes. 

 Cylindroleberis. 



Genus Cypridella*. 

 Cyprella*. 

 Entomis*. 



Family 4. Entomoconchid^. 



Genus Entomoconchus*. 

 Heterodesmus. 



Family 5. ConchceciadjE. 



Genus Conchoecia. 

 Halocypris. 



Section Cladocopa. 

 Family 6. Polycopid^. 

 Genus Polycope. 



Section Platycopa. 

 Family 7. CytherellidjE, 

 Genus Cytherella. 



t Described by the present author in ' Les Fonds de la Mer.' 



