
~ NicHoLtts—CoPrePopA FROM SOUTH AUSTRALIA 31 
Iwo seginents, is weakly geniculate apon the preceding seoment. The fifth legs 
ave somewhat. shorter than in the female but twice as long as wide, and similarly 
armed. Apart from the 5-seemented urosome, the male resembles the female in 
all other respects. 
This species is distinguished from all the other species by the genital seement 
and Wrogome of the female and by the elongate fifth leg, Ti resembles brewifurcatus 
in having the eaudal rami wider than long, but ditfers from it in 80 many respects 
that it must be rewarded as distinct, 
DiscoPonrms gen, nov, 
Body sub-cireular in outline, with a small projecting urosome, and the whole 
considerably flattened so as to be dise-shaped, The segments are without epimeral 
plates and the first segment is fused with the head; the third and fourth segments 
are fused and completely cover the fifth sezment dorsally. The urosome is very 
short, 3-sermeonted; (he genital serment 1s greatly enlarged and longer than the 
rest of the nrosome, ineliding the eaudal rami, and a little more than three times 
as wide as the other orosome segments. The month parts in weneral show the 
characters of the family. The first three pairs of legs have 3-seemented rami, the 
exopod of the fourth pair is 3-segmented and the endopod 2-sermented with re- 
duced setae, The fitth legs are well developed, 1-sezmented, and project poster- 
iorly from beneath the metasome, 
In the condition of the swimming legs this genus approaches Arctopontius : 
the first three paivs have wormal rami while in the fourth pair the endopod is re- 
duced to two segments, Sara’ genus moreover has a somewhat expanded metia- 
some and the cephalic appendages are not unlike those of his genus, The first an- 
tenna is of similar structure, though the sensory filament is sub-terminal; the 
secon antenna has the second and third segments considerably larger than either 
first or fourth, whereas in Arctopontius they are sub-equal, The siphon is less 
produced than in Sars’ genus, but the maxilla and maxilliped are very similar. Th 
Diseopontins Me body is sub-eireular ti milline and the female wrosome is 3-aeg- 
mented (in Arctapontius 4-sezmented) ; the third and fourth metasome segments 
are fused, an wousual feature, and dorsally cover the free fifth sezment. These 
seaments are all without ¢pimeral plates, whereas in Sars’ genus the segments are 
distinet and have well-developed epimera. The genital segment is enlarged in 
both. In conformity with the flattened body the bases of the swimming lees are 
very wide; the fifth legs are well-developed, whereas in Arctopontius they are 
represented only by setae, Tn shape this genus resembles Doropontius Thompson 
and Seott (1903), but their genus is clearly on Asterocherid in structure, Cleto- 
pontius of the same authors is also of a similar appearance, and helongs to the 
Dyspontidae, but differs in many respects, particularly the second antenna, max- 
illa, and fourth lees in which there is no endopod, The arosome is also 3-seg- 
mented in Cletopentius, but the anal segment ts no larger than. the presanal, 
whereas flere it is twice as large. 
DiscOPON TINS MTSOOMRS sp. nov. 
Ocuurrence. IX, 1 female. 
Female, Length 0°74 mm.; width 0-67 mm. The body has been described 
nder the characters of the genus. The first antenna has thirteen distinct see- 
ments, wilh a sensory flament. distally on the eleventh; tho second to eighth see- 
ments are fused. The second antenna is 4-se@mented, with a small exopod at- 
tached to the second seement at a little past the middle; the fourth segment is very 
short and bears terminally one spine and two setae, The oral cone is short and 
stout, slightly produced into a siphon. The maxillule has a short slender outer 
