66 
the inner two spines are articulated at the base. 
There is no other change and the first maxilla 
maintains this form throughout zoeal develop- 
ment. 
The scaphognathite of the second maxilla 
bears usually 8, occasionally 9, plumose setae 
on the anterior-outer margin. 
The exopodites of the first and second maxil- 
lipeds bear 6 plumose natatory setae. 
zoea m (Fig. 3): The first antenna (Fig. 
13) bears 3 aesthetes and 3 small setae on the 
tip. One aesthete is slightly larger and set apart 
from the other two in the terminal grouping 
found throughout further zoeal development. 
Small spines have been added distally on 
both lateral and medial spines of the second 
antenna (Fig. 19). 
The scaphognathite of the second maxilla 
may have 9 or 10, rarely 11, plumose setae on 
the anterior-outer margin. 
The exopodites of the first and second maxil- 
lipeds bear 8 plumose natatory setae. 
A pair of uniramous, 2-segmented uropods 
(Fig. 31) are now present on the anterior- 
ventral portion of the telson. Each of the distal 
segments bears 2 slender curving terminal setae 
armed with tiny spines distally ; the inner seta is 
longest. 
zoea iv (Figs. 4, 7) : The first antenna (Fig. 
14) now bears a subterminal tier of 2 aesthetes 
on the medial margin. 
The flagellum of the second antenna (Fig. 
20) appears in this stage as a slight rounded 
prominence to a small bud. 
The number of plumose setae along the outer 
margin of the scaphognathite of the second 
maxilla ranged from 15 to 21; most specimens 
had 17-20. 
The exopodites of the first and second maxil- 
lipeds bear 10 natatory setae, and the basipodite 
of the first maxilliped may have 8 setae along 
the inner margin in groups of 1-2-2-3 pro- 
gressing distally. 
Small buds of the third maxilliped and tho- 
racic appendages are present beneath the cara- 
pace, posterior to the second maxilliped. 
The exopodites of the uropods (Fig. 32) 
now bear 4 terminal setae of varying lengths; 
the third seta is the longest. The endopodite 
PACIFIC SCIENCE, Vol. XXI, January 1967 
may appear in this stage as a rudiment or a I; 
small bud. 
The telson (Fig. 9) has become somewhat j 
longer than wide and remains so in subsequent 
zoeal stages. 
zoea v (Fig. 5): The first antenna (Fig. 
15) bears usually 2, occasionally 3, subterminal 
groups of aesthetes along the medial margin; 
only one-fourth of the specimens dissected had j 
3 tiers of aesthetes. The majority of larvae had j 
4 subterminal aesthetes in groups of 2-2 ; rarely ; 
an additional aesthete was added to form groups j 
of 2-3 progressing distally. Those larvae with i 
3 subterminal tiers of aesthetes added them in 
groups of 2-2-3, rarely 1-2-3. 
The flagellum of the second antenna (Fig. | 
21) is now slightly shorter than to slightly 
longer than the 2 spines of the protopodite. 
The scaphognathite of the second maxilla i 
bears 24-39 plumose setae along the outer 
margin; most individuals had between 30 and j 
34 setae. 
The exopodites of the first and second maxil- | 
lipeds bear 12, rarely 11, natatory setae. The 
basipodite of the first maxilliped now bears 8 j 
setae along the medial margin in groups of 
1 -2-2-3 progressing distally. 
The third maxilliped and thoracic appendages 
have increased in size, curving under toward 
the thorax. 
The exopodites of the uropods (Fig. 33) 
now bear 5 or 6 setae of unequal length; the 
third seta is very long. More larvae had 5 than 
6 setae, a few had 5 on one side and 6 on the j 
other. The endopodite now varies in size from ; 
a small to prominent bud approximately 1/3 
the length of the exopodite. 
zoea vi (Fig. 6) : Now the first antenna j 
(Fig. 16) usually has 4 subterminal tiers of ; 
aesthetes in groups of 2-3-4-4 or 2-2-4-4 
progressing distally. Of 19 specimens 5 had 
only 3 tiers in groups of 2-3-4 or 2-4-4. 
The flagellum of the second antenna (Fig. 
22) has increased greatly in length and now 
dwarfs the spines on the protopodite. In speci- 
mens close to molting to megalopa, the seg- 
mentation of postlarval peduncle and flagellum 
can be seen beneath the cuticle. 
The scaphognathite of the second maxilla 
