9. THE CLASS CRUSTACEA
297
mm broad ; eggs large, rounded, in several longitudinal rows ; abdomen
of four segments, nearly cylindrical, 2.1-2.2 mm long, first through
third segments broader than long but fourth segment is longer than
broad ; caudal rami 0.83-0.85 mm long, each tapering slightly toward
distal end which has one subterminal and four claw-like terminal spines ;
first antenna of seven segments, 1.06-0.1 mm long, 0.25 mm wide a t
base, narrowed distally, with not very numerous small spiniform setae ;
terminal segment with four short setiform claws at tip and four setae
on posterior margin ; second antenna stout, of three segments, first
segment with a seta a t distal end, second segment with a shorter
pedunculate seta on inner margin, third with a group of three small
spines on inner margin and four terminal claws, one of which is stout
and the others are two-segmented; mandible terminating as pointed
blade with about twelve sharp teeth of which the two basal ones each
have an accessory tooth and a long spiniform ramus fringed with
spines on inner margin and four terminal claws, one of which is stout
seta, the latter with a very small spine on each side of its base, and
three spines close together near inner end; second maxilla comparatively short, with four teeth on distal inner margin and two small
mediodorsal spines near base ; maxilliped with rudimentary spine at its
bluntly pointed end ; first four legs biramous, each with three-segmented
rami ; proximal and middle podomeres of first through fourth endopodites with short spine a t outer end of each pectinate distal margin,
corresponding podomeres of exopodites with three similar spines and a
comb on each outer margin; each distal podomere of endopodites of
first through fourth legs with eight to nine spines, of which the outer
ones form three groups of two each with a comb a t each base and the
inner ones are longer, pectinate, and isolated ; corresponding podomere of exopodites with eleven to twelve spines of which the outer
ones form four groups of two each and a comb a t each base and the
inner ones are longer, pectinate and isolated; fifth leg uniramous,
digitiform, not reaching posterior end of genital segment, with one
seta and one spine a t tip and two short subterminal spines, each of
which is provided with a comb a t the base.
Adult male (Fig. 195) 4.1 mm long, resembling female in general
shape but with differing maxilliped and genital segment ; head 0.75 mm
long x 1.2 mm wide; thorax 1.75 mm long, tapering gradually posteriorly, 1.1 mm broad a t first segment, 0-67 mm broad a t fift,h segment ;
genital segment nearly quadrangular, 0.40 mm x 0.625 mm, with a
pair of ventral prominences bearing two setae on each posterior edge ;
abdomen of four segments, 1.5 mm long, first through third segments
broader than long, fourth segment longer than broad; caudal rami
297
mm broad ; eggs large, rounded, in several longitudinal rows ; abdomen
of four segments, nearly cylindrical, 2.1-2.2 mm long, first through
third segments broader than long but fourth segment is longer than
broad ; caudal rami 0.83-0.85 mm long, each tapering slightly toward
distal end which has one subterminal and four claw-like terminal spines ;
first antenna of seven segments, 1.06-0.1 mm long, 0.25 mm wide a t
base, narrowed distally, with not very numerous small spiniform setae ;
terminal segment with four short setiform claws at tip and four setae
on posterior margin ; second antenna stout, of three segments, first
segment with a seta a t distal end, second segment with a shorter
pedunculate seta on inner margin, third with a group of three small
spines on inner margin and four terminal claws, one of which is stout
and the others are two-segmented; mandible terminating as pointed
blade with about twelve sharp teeth of which the two basal ones each
have an accessory tooth and a long spiniform ramus fringed with
spines on inner margin and four terminal claws, one of which is stout
seta, the latter with a very small spine on each side of its base, and
three spines close together near inner end; second maxilla comparatively short, with four teeth on distal inner margin and two small
mediodorsal spines near base ; maxilliped with rudimentary spine at its
bluntly pointed end ; first four legs biramous, each with three-segmented
rami ; proximal and middle podomeres of first through fourth endopodites with short spine a t outer end of each pectinate distal margin,
corresponding podomeres of exopodites with three similar spines and a
comb on each outer margin; each distal podomere of endopodites of
first through fourth legs with eight to nine spines, of which the outer
ones form three groups of two each with a comb a t each base and the
inner ones are longer, pectinate, and isolated ; corresponding podomere of exopodites with eleven to twelve spines of which the outer
ones form four groups of two each and a comb a t each base and the
inner ones are longer, pectinate and isolated; fifth leg uniramous,
digitiform, not reaching posterior end of genital segment, with one
seta and one spine a t tip and two short subterminal spines, each of
which is provided with a comb a t the base.
Adult male (Fig. 195) 4.1 mm long, resembling female in general
shape but with differing maxilliped and genital segment ; head 0.75 mm
long x 1.2 mm wide; thorax 1.75 mm long, tapering gradually posteriorly, 1.1 mm broad a t first segment, 0-67 mm broad a t fift,h segment ;
genital segment nearly quadrangular, 0.40 mm x 0.625 mm, with a
pair of ventral prominences bearing two setae on each posterior edge ;
abdomen of four segments, 1.5 mm long, first through third segments
broader than long, fourth segment longer than broad; caudal rami