142 
THE MOUTH-rARTS OF THE SHORE CRAB. 
Explanation of the lettering of the figures. 
ah. 
ac. 
ap. 
ar.ch. 
ar.mp. (2, i 
art. 
. b. 
h: 
c. 
cl>. 
col. 
auteuaa. 
antennule. 
abdomen. 
accessory muscles. 
apophysis. 
avtlirobraiichs of chelipetl, or 
stumps of same. 
'). arthrobranchs of niaxillipeds. 
articulation, 
basis. 
branchial ridge, 
carpus, 
cheliped,. 
collecting- space. 
ex. coxa. 
cx.s. coxopoditic set«. 
d. dactylus. 
e. eye. 
eb.c. epibranchial channel. 
eb.sp. epibrauchial space. 
en. endopodites. 
en.mp. {1,S). endopodites of niaxillipeds. 
ep.(l,S,3). epipodites. 
e^nst. epistome. 
et. {1,2). endites of first maxilla. 
ex. exopodite. 
e.T.mp. {1,2). exopodites of maxillipeds. 
e.vh. c. exhalent canal or passage. 
e.rh. 0. exhalent opening. 
Jl. fiagella. 
Jiff, flange. 
/(. hinge. 
hy. hypobranchial space. 
, , I openino-3 in front of 2'ills, 
hy. ar. ch. i i 
, „ ,-, ns > leadins' to hypobraiichial 
hy.plb. {1,2). I n Ji 
I space. 
i. ischium. 
i.fl. inner floor. 
i.l. inner lacinia, 
j'.r. inner roof. 
in.o. approach to iiThalent opening. 
I. {1,2). cleft lobes of maxilla. 
Im. labrinn. 
m. merns. 
jnd. mandible. 
7np. (1, 2,3). maxillipeds. 
inih. mouth. 
o.l. outer lacinia. 
ojl. outer floor. 
o.r. outer roof. 
o.mp. opening leading to gill-chamber, 
in front of third maxilliped. 
o.M.E. opening of Milne-Edwards. 
p. propus. 
p.hy. posterior opening of hypo- 
branchial chamber. 
pb. {1, 2). podobranchs. 
pel. pericardial lobe. 
pgn. paragnathum. 
plh.{l,2). pleurobranchs. 
2)lp. palp of mandible. 
j)r. {1,2,3). processes upon rim of branchio- 
stegite which meet corre- 
sponding processes above 
articulations of legs. 
pr' . processes above articulation of 
legs. 
sc. scaphognatliite. 
sd. sclerite. 
St. .sternum of third maxilliped. 
Si!', fused sterna of mouth-parts in 
front of third maxillipeds. 
t.i.ad. tendon of inner adductor, 
t.o.ab. tendon of outer abductor. 
t.o.ad. tendon of outer adductor. 
w.l. (1,2,3,4). walking-legs. 
