Lep e op ht heir us dissimulatus — Lew is 
237 
The protopodite tapers distally, the lateral mar- 
gins are slightly irregular, and the distal margin 
is continuous with the outer lateral margin. The 
exopodite is two-segmented, the second segment 
2 Vl times the length of the first. The base of 
the spine-bearing first segment of the fifth chal- 
imus is visible inside the first segment of the 
fourth chalimus; the lateral margins of the 
fourth chalimus segment are convex. The spine- 
bearing segment mentioned above and present 
in the fifth and sixth chalimus in addition to the 
adult replaces the first segment of the third and 
fourth chalimus; the second segment of these 
two stages remains as the second segment, which 
later divides to form the second and third seg- 
ments. The lateral and distal margins of the sec- 
ond exopodite segment of the fourth chalimus 
are continuous, the distal end is broadly rounded, 
and the surface gives rise to three lightly plu- 
mose setae. The endopodite is two-segmented 
although the division between the first segment 
and protopodite is indistinct and incomplete. 
The second segment is as wide as long and has 
a broadly rounded outline with the lateral and 
distal margins being continuous. The distal sur- 
face of the segment bears four lightly plumose 
setae. 
The third thoracic leg of the fifth chalimus 
stage (Fig. 20*?) possesses characteristics very 
similar to those of the adult. The protopodite 
is one-segmented and greatly expanded from the 
previous stage. The sternal plate, connecting the 
protopodites of the two legs, is broad and forms 
a laminate projection from the posterior ventral 
surface of the cephalothorax. The exopodite is 
still two-segmented, the first segment possessing 
a strongly-developed, spinelike projection from 
the inner distal surface. The proximal end of the 
first segment is distinct from the protopodite 
ventrally although it is still fused dorsally to the 
protopodite and the distal end to the second 
segment. The first segment, other than the proc- 
ess, is short, the width being greater than the 
length. The second segment is broadly rounded, 
the lateral margins continuous with the distal. 
The proximal end of the segment is narrow and 
the segment appears palm-shaped; the greatest 
width is slightly more than two-thirds of the 
length. The endopodite is two-segmented; the 
first segment is twice as wide as long and ap- 
pears as a narrow band with a swollen outer 
lateral region. The second segment is attached 
to the inner distal surface of the first and is 
broadly rounded, the lateral and distal margins 
being continuous. The greatest length of the 
second segment is slightly greater than that of 
the first; the width and length are, however, ap- 
proximately equal. 
With minor exceptions, the third thoracic 
leg of the sixth chalimus (Fig. 20/) and the 
adult (Fig. 20g) are the same. The protopodite 
of the sixth chalimus is broadly flattened and 
laminate; the lateral and distal margins are con- 
tinuous. The exopodite is now three-segmented, 
the first segment forming the base for a strongly 
developed, spinelike process that projects from 
the distal inner margin as in the preceding stage. 
The lateral margins of the first segment are ir- 
regular, the outer being generally convex and 
the inner almost straight. The second segment 
is short and flared from the narrow proximal to 
broad, concave distal end. The third segment is 
also short, being approximately equal in length 
to the second, and the width is slightly greater 
than the length; the lateral margins of the seg- 
ment are rounded and continuous with the 
rounded distal margin. The endopodite is two- 
segmented, the first segment broad, its width 
approximately l l /2 times its length. The outer 
two-thirds of the distal margin of the first seg- 
ment is convex, the inner one-third concave; 
the outer lateral margin is continuous with the 
distal margin, and the inner margin is irregular. 
The second segment is slightly shorter than the 
first segment and is attached to the concave in- 
ner distal surface of the first. Both of the lateral 
margins are continuous with the distal margin 
in the second segment. 
The protopodite of the adult third thoracic 
leg (Fig. 20g) is broader than that of the sixth 
chalimus; the first endopodite segment is slightly 
longer, although not wider, and the armature 
of the appendage has changed slightly in the 
moult from the sixth chalimus to the adult. 
Other than these differences, the appendages of 
the two stages are the same. 
Thoracic Leg IV 
The armature and character of the mem- 
branes, spines, and setae comprising the arma- 
ture are given in Table 5. 
The uniramous fourth thoracic leg is first 
