506 
PACIFIC SCIENCE, Vol VII, October, 1953 
Fig. 2. Eury femora yukonensis n. sp. Female, a. Leg 
5; b, leg 5, detail of armature of exopod segments 1-2; 
c, antennule, aesthete of segment 11. 
segments, those of 9 and 12 longest, subequal 
to each other (Fig. 3). Segments 14-16 very 
swollen. Segments 17 and 18 with marginal, 
hyaline, depressed processes ornamented with 
double row of spinous serrations. Penultimate 
segment with proximal curving group of long, 
slender spinules, with striated lamina follow- 
ing; distal portion without ornamentation. 
Terminal segment somewhat longer than pre- 
ceding segment (50:40). 
Leg 5 (Fig. 3) having both rami 4-seg- 
mented. Basal portion narrow, first segment 
of left leg longer than that of right. Right 
leg characterized by an extremely long ter- 
minal segment. Relative lengths of basipod 
2 and exopod segments 1 and 2: 40:50:73. 
Inner distal portion of second basipod seg- 
ment swollen a little. Terminal segment not 
only extremely long but very slender, without 
any inner basal swelling, and with distal inner 
margin very irregular. 
Second basipod segment of left leg short, 
swollen inside. Terminal segment a little long- 
er than exopod 1 (45:40), apex broadened 
but hardly produced on either side; inner por- 
tion and most of anterior side set with short 
hairs. 
COPEPODID STAGES (Fig. 4). Copepodid 
stages 3, 4, and 5 were present in the collec- 
tions. All had a prominent dorsal protuber- 
ance of the cephalic segment as in the adult. 
Stage V is briefly described. 
Female, stage V: Total length 1.29 mm. 
(metasome 0.8, urosome 0.49 mm.). Uro- 
some 3-segmented, genital segment without 
lateral protrusions. Proportion of caudal rami 
to rest of urosome 12:20. Antennule 23-seg- 
mented. Leg 5 having inner process of exopod 
short, lateral spines all short as in adult, ter- 
minal spine also about as long as exopod, 
spinous process between terminal spines more 
pronounced than in adult. 
Male, stage V: Total length 1.175 mm. 
(metasome 0.725, urosome 0.45 mm.). Uro- 
some 4-segmented. Leg 5 with 4-segmented 
rami, left a little shorter than right, apical 
segments very similar, others showing a slight 
asymmetry, most pronounced difference be- 
ing rounded protrusion of inner margin of 
right basipod 2. 
DIAGNOSTIC CHARACTERS. The diagnostic 
characters of this species may be summarized 
as follows: 
Pronounced dorsal protuberance of cephalic 
segment in both sexes in adult and copepodid 
stages 3-5. 
Genital segment of female strongly con- 
stricted, proximal lateral lobes wider than dis- 
tal; genital operculum hemispherical. 
Urosome and caudal rami in both sexes 
lacking dorsal ornamentation. 
Caudal rami of female shorter than seg- 
ments 2 and 3 combined; those of male short- 
er than segments 3-5, their length about 7 X 
their width. 
