32
THE BIOLOQY OF EUPHAUSIIDS
7b. Sixth abdominal segment almost or fully as long as sum of
the two preceding segments.
9a. Antennules with the upper flagellum somewhat or considerably longer than the sum of the two distal peduncular joints. Terminal process of the copulatory organs
a little expanded on the inner side towards the terminal
margin which is convex with fine saw teeth along the
front side; proximal process with end somewhat
expanded and curved backwards, with the terminal
margin transverse and serrate
. . I .
vicina
9b. Antennules with the upper flagellum somewhat shorter
than the sum of the two distal peduncular joints.
Terminal process of the copulatory organs distally
expanded at both sides and especially outwards, with
the terminal margin long, oblique, conspicuously
emarginate, without serration, while the terminal inner
part is a projecting, broadly rounded lobe, the terminal
outer part subtriangular with the free angle narrowly
rounded, proximal process with a very short terminal
part strongly curved, slender a t the base of the curvature
and the end itself distinctly broader with the margin
transverse
. . .. .. .. . . macrura
6b. Lateral denticle anterior to mid-point of inferior margin of
raschii
carapace. Second thoracic leg slightly, or not a t all, elongate
Genus Pseudeuphausia
Carapace has a long frontal plate, the broad end transversely cut
off, without a rostrum; a small tooth near the posterior end of the
lateral margin. Females carry their eggs. Wang and Chen (1963)
described P. sinica and compared it with P. latifrons.
Carapace with prominent median keel, antennule with spine, mandible with
well-developed palp, and maxillule without exopod
. . . . latifrons
Carapace without prominent median keel, antennule without spine, mandible
without palp, maxillule with exopod
. . .. .. .. sinica
Genus Euphausia
la. Species with two pairs of lateral denticles on the carapace. No dorsal
process on the third to fifth abdominal segment. The male copulatory
organ with a slender, thin-walled secondary process near the distal end
of the proximal process.
THE BIOLOQY OF EUPHAUSIIDS
7b. Sixth abdominal segment almost or fully as long as sum of
the two preceding segments.
9a. Antennules with the upper flagellum somewhat or considerably longer than the sum of the two distal peduncular joints. Terminal process of the copulatory organs
a little expanded on the inner side towards the terminal
margin which is convex with fine saw teeth along the
front side; proximal process with end somewhat
expanded and curved backwards, with the terminal
margin transverse and serrate
. . I .
vicina
9b. Antennules with the upper flagellum somewhat shorter
than the sum of the two distal peduncular joints.
Terminal process of the copulatory organs distally
expanded at both sides and especially outwards, with
the terminal margin long, oblique, conspicuously
emarginate, without serration, while the terminal inner
part is a projecting, broadly rounded lobe, the terminal
outer part subtriangular with the free angle narrowly
rounded, proximal process with a very short terminal
part strongly curved, slender a t the base of the curvature
and the end itself distinctly broader with the margin
transverse
. . .. .. .. . . macrura
6b. Lateral denticle anterior to mid-point of inferior margin of
raschii
carapace. Second thoracic leg slightly, or not a t all, elongate
Genus Pseudeuphausia
Carapace has a long frontal plate, the broad end transversely cut
off, without a rostrum; a small tooth near the posterior end of the
lateral margin. Females carry their eggs. Wang and Chen (1963)
described P. sinica and compared it with P. latifrons.
Carapace with prominent median keel, antennule with spine, mandible with
well-developed palp, and maxillule without exopod
. . . . latifrons
Carapace without prominent median keel, antennule without spine, mandible
without palp, maxillule with exopod
. . .. .. .. sinica
Genus Euphausia
la. Species with two pairs of lateral denticles on the carapace. No dorsal
process on the third to fifth abdominal segment. The male copulatory
organ with a slender, thin-walled secondary process near the distal end
of the proximal process.