(52h) 
XXIV.—The Entomostraca of the Scottish National Antarctic Expedition, 1902— 
1904. By Thomas Scott, LL.D., F.L.S. Communicated by Dr J. H. 
AsHwortH. (With Fourteen Plates.) 
(MS. received January 24,1912. Read February 19, 1912. Issued separately November 15, 1912.) 
CONTENTS. 
PAGE 
Introductory Statement. : : : : : : ; j i : . 521 
Systematic Part— 
Copepoda . ; : : : : : , : ‘ ; : . 527 
Cladocera . ; ‘ : ; : ; . 580 
Ostracoda . ‘ : ; F : ; ‘ ‘ é : : ; . 580 
Alphabetical Index . ; : : : : : : ; : : : . 589 
Addenda . a, ee, : ‘ 7 : : ; : : : : : 599 
INTRODUCTORY STATEMENT. 
The Entomostraca recorded here were collected by the s.y. Scotia on its way to 
and from the Antarctic, and also while carrying on investigations there during the 
years 1902 to 1904. The Hntomostraca in these collections belong chiefly to the 
Copepoda, but the Cladocera and~ Ostracoda are also represented, the last by a 
considerable number of species. These three groups are described below in the order 
mentioned. 
Tuer CoPpEPoDA. 
The Copepoda recorded in the following pages number considerably over one 
hundred species. A fairly large proportion of them belong to the Calanoida and to 
one or two other groups of pelagic forms; these were, for the most part, obtained in 
samples of plankton—chiefly surface gatherings collected by tow net at various stations 
on the outward voyage betweeen Cape Verde and the Falkland Islands. On the other 
hand, most of the Harpacticoida, of which there are a good number, are from the 
neighbourhood of the South Orkney Islands, but some of them were also obtained in 
siftings from material brought up in the dredge or trawl net, and amongst organisms 
washed from floating Gulf-weed. 
Most of the pelagic or free-swimming species from the tow-net collections are more 
or less widely distributed, and have been described in various published works, but some 
of them are tolerably rare. The Harpacticoida and other demersal forms are, however, 
not so well known, and a considerable number of those recorded here appear to be 
undescribed ; a few of them are closely related to British or other northern species, and 
seem to lend some support to the idea of a bipolar distribution. 
The occurrence at places so far distant as the Falklands and South Orkneys of 
_ demersal forms identical with, or closely allied to, those of Britain and Norway has a 
bearing on the question of distribution different from that concerning organisms living 
TRANS. ROY. SOC. EDIN., VOL. XLVIIL, PART III. (NO, 24). 78 
