70 
Records of the Australian Museum (2009) Vol. 61 
Key to species 
In using this key, it is necessary to be aware of the variability between individuals and populations of the same 
species. Comparative features in the couplets are arranged so the most reliable are given first, and the least 
reliable last. While almost all specimens will fit all key features of a given species, occasionally individuals 
or populations will be aberrant and disagree with one feature, usually the last. In such cases identification 
should be confirmed using the additional characters given for each species in square brackets. 
1 Telson with c. 50 dorsal spines in each row; 32 body segments; most 
antennal segments with >12 spines. L. birchii Spencer & Hall 
[Also: mature specimens large, generally >18 mm long and up to 30 mm; L:D 
ratio c. 1.5; 14-16 growth lines; dorsal carinae of growth lines reach forward to 
proceding growth zone; dorsal surface of telson double-curved in a sinewave; 
caudal claws evenly curved and with >10 dorsal spines at midlength; carapace 
with dorsoposterior corner sharp, composed of a protruding growth line carina; 
eggs round with parallel grooves; carapace usually translucent yellow-brown.] 
-Telson with < 25 dorsal spines in each row; 24-26 body 
segments; most antennal segments with <10 spines.2 
2 Dorsal margin of carapace with irregular, asymmetrical 
growth line carinae; carapace with robust growth lines; caudal 
claws with <3 dorsal spines at midlength . 3 
-Dorsal margin smooth, or almost so with only very minor steps 
at each growth line-dorsal margin junction; carapace usually, 
but not always, with indistinct growth lines; caudal claws with 
usually >4 dorsal spines at midlength. 5 
3 Posterior edge of carapace not, or just barely expanded beyond 
dorsoposterior corner, latter usually bearing a prominent spine; an- 
teriormost dorsal telsonic spine 1.5-2 times size of next few spines; 
carapace hinge line of male straight or almost so. L. tatei Spencer & Hall 
[Also: mature specimens small, usually <10 mm; L:D ratio c. 1.6; 7-11 (usually 
<9) growth lines; growth line carinae barely extending into preceding growth zone; 
these carinae variously developed, sometimes hardly developed at all; 5-7 spines 
on middle second antennal flagellomeres, all arranged linearly; dorsal surface of 
telson straight or evenly and slightly concavely curved and bearing two rows of 
9-13 (usually c. 12) spines, these sometimes unevenly sized and spaced; caudal 
claws with straight basal section bearing >12 (rarely as few as 8) proximal setae 
and <3 dorsal spines at midlength; eggs round with grooves parallel only for short 
distances; carapace usually translucent yellow-brown.] 
-Posterior edge of carapace expanded into wide curve protrud¬ 
ing beyond the dorsoposterior corner, latter bearing a weak 
spine, if any at all; anteriormost dorsal telsonic spine <1.5 times 
as large as the next few spines; carapace hinge line markedly 
curved, even in males. 4 
4 Dorsal hinge line of carapace in umbo area convexly curved; telson 
with 12-14 spines evenly spaced; anteriormost telsonic spine c. 1.5 
times as large as next few spines .L. pilbarensis n.sp. 
[Also: mature specimens c. 10 mm long with 9-11 growth lines; L:D ratio c. 1.5; 
dorsal margin of carapace stepped, and with hardly any carinal outgrowths; up to 9 
spines on middle flagellomeres of second antenna, all arranged linearly; caudal claw 
with straight basal section bearing c. 10 proximal setae and <3 (rarely more) dorsal 
spines at midlength; dorsoposterior comer of carapace blunt with projection at the 
end of the growth line; eggs round with many (>12) narrow, sharp spikes, pitted 
between these spikes; carapace yellow with very distinct dark growth lines.] 
Dorsal hinge line of carapace in umbo area concavely curved, i.e. 
depressed; telson with 14-18 spines unevenly spaced; anteriormost 
telsonic spine slightly bigger than next few spines. 
L. paradoxa n.sp. 
