
NICHOLLS—COPEPODA FROM SouTH AUSTRALIA 25 
5. First untenna 10- or 11-segmented , Se at + » & 
Firat antenna §-segmented .. “4 -- . £ 
6, Exopod of second antenna with lwo setae; end eogmunt of first exepod with two inner setae 
thorelli. (Giesbrecht) 
Kxopod ot second antenna without setae; ond aegment of first exopod with three inner setae 
similig ap. nov. 
7, Width of eephalosome about four-tifths of its gin “- tenwis (Giesbrecht )- 
Width of cephalosome equal to its length : ve gracilis Wilaon, 
& First antenna 10-segmented; exopod of sceond chtadin with two setae; immer Jobe of 
maxillule with loug plumose seta fe capitalis (Giesbrecht). 
Hirst anteios 9-sepmented; vered of second antenna without setae; inner lobe of maxillule 
with short seta... an " ee ..  Jatus ap. mov. 
It. is uneertain whether innominatus should have been included. Brady’s 
gpecimen was apparently damaged, but the urosome which he figures shows 
the genital segment of the same width throughout. whereas it is characteristic of 
the genus that it should be very much widened anteriorly. 
ORYPTOPONTIUS SIMILIS Sp, 2OV, 
Occurrence. X, 1 female, 1 male. 
Female. Length 1:30 mm, The body is of similar shape and proportions to 
thorelli, though less acutely pointed anteriorly. The first antenna is 10-segmented, 
with the third to seventh and ninth to eleventh segments fused. The second an- 
tena has a gmall unarmed exopod; the end segment is without lateral setae but 
has a row of fine hairs, The siphon reaches to the base of the first legs but not, 
beyond, The maxillule has both lobes slender, the outer two-thirds as long as 
the inner and armed with a short seta and small spine, the inner lobe armed with 
two slender spines. ‘The maxilla and maxilliped are very like those of thorelli. 
The swimming legs are normal, with the following seta formula: 
endopod., exopod, 
pa. 1.3.921. 1,1.833. 
pz. 12,521. 1,1.423- 
pa, 1.8.321. 1,1.423. 
ped. — 1.1,423, 
The fitth leg is twice as long as wide, with one spine and a seta. The candal rami 
are longer than wide (about 4:3). 
Male. Length 1-02 mm. The body is more slender than that of the female, 
as is usual in this genus, and the urosome is fivesegmented, The first. antenna. has 
eleven distinet segments, the large sensory filament being placed sub-terminally 
on the end segment, There is a series of long thin sensory filaments distributed 
as follows; one on Lhe secoud and eighth segments, two on the sixth and ninth 
and four on the third segment, The ninth sxeoment also has two short spines near 
the bases of the filaments. The mouth parts and lees areas in the female and the 
caudal rami have a sindlar proportion and armature. 
This species is very close to thorelli, particularly in the shape and proportions 
of the body, its size, the first antennae, maxillae and maxillipeds, 1 differs in 
the proportions aid armature of the maxillale and in the armature of the second 
antenna and first lee. In this leg in therelli the seta formula is 1+1+ 321; 1-1-2238, 
Ni is untortuuate that Gieshreeht (1899) has vot iWhustrated the fourth logs of the 
species of this genus described therein as.there is some variation m the second seg- 
ment of the basipod of this lee in the species found here. In this species there 
isa smuall prominence on this sezmenut, which may represent the missing endopod. 
In longipes, deseribed below, this promineuee ig well developed, whereas the two 
other species deseribed here are without any such prominence. 
