52 FRESHWATER AND LAND CRAYFISHES OF AUSTRALIA 
Austroastacus hemicirratulus (Smith and. Schuster). 
(PI. X, figs. 1-3; PI. XI, figs. 1-3.) 
Engaeus hemicirratulus Sm. and Sch., Proc. Zool. Soc. Lond., 1913, 
p. 123, pi. 20-22, figs. 34, 35, 37, 38. 
Male . — Length of average adult specimen, 70 mm. 
Rostrum broad, apex blunt, with two conspicuous tufts of long bristly setae 
at apex ; carinae indistinct, but each indicated by a row of long setae. 
Eyes large. First antennae each with one flagellum. Second antennae 
short and slender, one-eighth longer than first ; squames each with a very 
short inner lobe terminated by a long slender sharp spine. Interantennal 
spine short, broad, bluntly pointed. Exopods of third maxillipedes absent. 
Carapace punctate, minutely tuberculate on branchiostegites ; posterior 
twice as broad as anterior ; one and one-half times higher than broad, three 
times longer than broad. Carapace very short posteriorly, highly vaulted, not 
covering top of last pereopod, and only part of podobranchs of second and 
third pereopods. Cervical groove and branchio-cardiac grooves strongly 
impressed, areola narrow. 
Sternal keel obsolete, feebly rounded, lateral processes small, sharp below 
second pereopods, posterior pair rounded, deeply grooved ; processes between 
fourth pereopods long and slender. 
Abdomen punctate, with numerous tufts of long bristly setae ; first segment 
broad and rounded, without lobes or spines at lateral margins. Telson large 
and rounded, more than twice the size of uropods, entirely calcareous, without 
spines, but having a large round swelling in middle below anterior margin; 
uropods shorter than telson, small and slender, calcareous throughout, with- 
out trace of transverse sutures, each with a smooth carina in middle ending in 
a sharp spine almost on posterior margin ; telson and uropods covered by 
numerous tufts of long bristly setae. 
Great chelae with numerous punctures and tufts of long bristly setae; 
propodus very stout, two and one-half times longer than broad, bordered 
by a row of large tubercles on upper, lower and posterior margins, three or 
four large tubercles on cutting edge ; dactylus stout, with three or four large 
tubercles on cutting edge, several tufts of long bristly setae on upper margin ; 
a smooth longitudinal ridge on upper and lower surface of propodus and 
dactylus; upper margin of merus smooth or feebly serrated; upper margin 
of carpus with a single row of large tubercles. 
Gill formula : 
Podobranchiae 
Arthrobranchiae 
Pleuro- 
branchiae 
Total 
Anterior 
Posterior 
vii 
ep. 
0 
0 
0 
ep. 
vfix 
1 
1 
0 
0 
2 
ix 
1 
1 
1 
0 
3 
X 
1 
1 
1 
0 
3 
xi 
1 
1 
1 
1 
4 
xii 
1 
1 
1 
1 
4 
xiii 
1 
1 
1 
1 
4 
xiv 
0 
0 
0 
0 
0 
6 + ep. 
+ 6 
+ 5 
+ 3 
= 20 ep. 
