REPORT ON THE OSTRACODA. 5 



S. Brady, appear in our list only on the strength of their having been seen in anchor- 

 mud from a European Station, Vigo Bay. The fact, however, is instructive, and leads 

 to the inference that these particular species do not much overstep the European bound- 

 ary ; the Vigo specimens, indeed, are in the case of some species depauperated, and ha-\'e 

 not the well-marked characters which usually belong to British examples. Amongst 

 flimiliar northern species which reappear in distant parts of the world, besides those which 

 have already been noted as occurring at Kerguelen's Land, are Paracypris polita, G. 0. 

 Sars ; Pontocypris tngonella, G. 0. Sars ; Bairdia acanthigera, G. S. Brady ; Bairdia 

 crosskeiana, G. S. Brady ; Cytliere crispata, G. S. Brady ; Cythere prava, Baird ; and 

 Cythere speyeri, G. S. Brady. And this list might be further extended were I to add the 

 names of some which were first described from sponge-sand specimens, supposed to have 

 come from the Levant, but which, I now think, were very probably from the East Indies. 

 Except Krithe hartonensis, Jones ; Cythere cancdiculata, Reuss ; Cythere p)olytrema, G. S. 

 Brady ; and perhaps Bairdia ovata, Bosquet, no Ostracoda have been met with which can 

 be referred with certainty to species described by palaeontologists ; ^ but the somewhat 

 strained and diagrammatic drawings given by many authors render identification extremely 

 difficult, and it is not unlikely that, were the actual specimens at hand for comparison, some 

 further identifications might be made. As to the specimens which I have thought it 

 allowable to refer io Pontocy p>r is f aha, Reuss (see p. 37), some doubt may be entertained, 

 but they bear a very close Kkeness indeed to shells so named by me in a memoir on the 

 Ostracoda of the Antwerp Crag, from which formation Cythere p>olytrema also was obtained. 



The labour attending the mere preparation of a quantity of dredged material for 

 microscopic investigation — the sifting, picking out, and sorting of specimens — is neces- 

 sarily very great, and to treat in this way the whole of the samples brought home by 

 the Challenger would have been impossible. The' dredgings reported upon in this 

 memoir were, however, carefully selected so' as to include representatives of all kinds 

 of bottoms, taken from all parts of the area worked over by the expedition. And, I 

 must add, that, with the limited leisure at my command, I should have been quite 

 unable to get through the work in any reasonable time, had I not been favoured with 

 the kind help of my brother, Mr H. B. Brady, F.R.S., whose materials — carefully pre- 

 pared for the examination of the Foraminifera, and, therefore, equally available for the 

 Ostracoda — have been entirely placed at my disposal. To him my best thanks are due, 

 and, likewise, to Mr Walter Purkiss, for the care and labour which he has bestowed upon 

 the drawing and lithographing of the plates ; all of which, I can attest, give faithful and 

 characteristic representations of the species portrayed. 



In the arrangement of the main groups of the Ostracoda I follow G. 0. Sars, whose 

 subdivision into sections and families is exhibited in the following synopsis, with the 

 addition only of the Darwinellid.e, — a family described by Mr D. Robertson and myself 

 since the publication of Professor Sars' memoir. 



1 In tkis statement I leave oiit of view Post-Tertiarj- species, cf which several might have been iiametl as occurring 

 amongst the Challenger dredgings. 



