Copepods in Southeastern Pacific — Grice and Hulsemann 
331 
diagnosis: Female. Body slender. Length of 
abdomen and furca contained 2.5 times in 
cephalothorax. Head and first thoracic segment 
separate. Fourth and fifth thoracic segments 
fused. Rostrum of moderate size, pointed down- 
ward and forward. Posterior lateral margin with 
patch of hair, in lateral view rounded, in dorsal 
view smoothly rounded. Abdomen consisting of 
4 segments. Genital segment long and slender; 
in dorsal view almost symmetrical, moderately 
widening on both sides of proximal half, be- 
coming slender again in distal half. Genital 
swelling produced ventrally; in lateral view the 
posterior part more produced than the anterior 
due to the shape of the genital flaps. Posterior 
margins of abdominal segments smooth. Anal 
segment very short. First antenna reaching to 
fourth thoracic segment, consisting of 23 free 
segments (8 and 9, and 24 and 25 are fused). 
First and second exopodal segments of first 
swimming foot incompletely separated. External 
spine of second exopodal segment of second 
foot almost reaching tip of first external spine 
of third exopodal segment. Total length 8.50- 
9.41 mm. Holotype: usnm 120530. 
Male. Body slender. Abdomen contained 2.3 
times in cephalothorax. Rostrum small, slender, 
directed downward and somewhat backward. 
Forehead in side view rounded. Head and first 
thoracic segment fused as are fourth and fifth 
thoracic segments. Posterior lateral margin of 
last thoracic segment asymmetrical: left side 
rounded, protruded; right side shorter, bluntly 
triangular. Abdomen consisting of 5 segments. 
Right side of first abdominal segment slightly 
longer than left. Anteriorly there is a dorsal 
button, somewhat set off toward the right side; 
there is also a V-shaped ridge. The distal mar- 
gins of second to fourth abdominal segments 
carry flat, rounded teeth. Anal segment very 
small. First antenna reaching end of genital seg- 
ment; consisting of 22 free segments (segments 
8-10, and 24 and 25 are fused). Fifth feet 
longer than abdomen. Endopod of right fifth 
foot as long as first exopodal segment which 
carries a tubercle in about its middle. Distal end 
of exopod broken off. Endopod of left fifth 
foot small, curved. First exopodal segment of 
left fifth foot flattened, second segment carry- 
ing a recurved tooth. Inner distal end of this 
segment prolonged into a slender lamella with 
smooth outer margin; inner margin beset with 
row of teeth separated into proximal and distal 
portion. Finely striated finger-shaped process 
about as long as toothed lamella. Haired 
tubercle bilobed. Pointed third exopodal seg- 
ment only slightly longer than toothed lamella 
bearing the usual patch of hair. Total length 
8.50 mm. Allotype: usnm 120531. 
remarks: The female Euchaeta regalis is 
similar to E. dubia Esterly, E. hanseni With, 
and E. sarsi Farran. It is readily distinguished 
from these species by the more slender abdomen 
and the peculiarly shaped genital protuberance. 
The male of E. regalis shows close affinities to 
the males of E. dubia Esterly and E. hanseni 
With. It differs from the male of E. dubia in 
the absence of hyaline spines on the postero- 
lateral margin of the last thoracic segment 
and in the structure of the toothed lamella on 
the left fifth foot. This lamella is spoon-shaped 
and smooth on the external margin. The lamella 
of E. dubia has a bifid apex and carries teeth on 
the external as well as on the internal margin. 
In the male of E. hanseni the lamella bears teeth 
also along the external margin. 
Euchaeta vorax n. sp. 
Figs. 49-52 
occurrence: Station 21, 1 female. 
diagnosis: Female. Body and abdomen 
slender. Length of abdomen and furca con- 
tained 2.2 times in cephalothorax. Head and 
first thoracic segment separated by a fine line, 
fourth and fifth thoracic segments fused. 
Rostrum slender, pointed downward and for- 
ward. In lateral view posterior lateral margin 
of fifth thoracic segment slightly angular, with 
patch of hair. Hair also present on posterior 
lateral margin of same segment. Abdomen con- 
Figs. 53-59. Euchaeta weberi (A. Scott), male. 53, Dorsal view; 54, lateral view; 55, rostrum, lateral 
view; 56, posterior end of thorax, left lateral view; 57, posterior end of thorax, right lateral view; 58, distal 
end of exopod of left fifth foot; 59, distal end of exopod of left fifth foot, another view. 
Figs. 60-62. Xanthocalanus pinguis Farran, female. 60, Endopod of second maxilla (8.91 mm specimen) ; 
61, fifth foot (8.91 mm specimen) ; 62, fifth foot (8.00 mm specimen). 
