AUSTRALIAN FRESHWATER AND LAND CRAYFISHES 
35 
Island. Each of the five known species is found in Victoria, 
the most widely distributed species being G. gracilis Clark. It 
is found in Victoria, Tasmania and Kangaroo Island. 
All the sjDecies live in the marshy ground along the banks 
of rivers or creeks. 
Key to species of GEOCIIARAX Clark. 
Rostrum slender. 
Great chelae slender; propodus with upper and lower 
margins smooth . . . . . . . . , . . . laevis sp. nov. 
Great chelae slender; propodus with upper margin 
serrated, lower margin smooth . . . . . . gracilis Clark. 
Rostrum broad. 
Great chelae slender . . . . . . . . . . lyelli Clark. 
Great chelae very stout ; dactylus sickle shaped . . falcata sp. nov. 
GeocJiarax laevis sp. nov. 
Plate X, Fig. 4. 
Length 52 mm. 
Rostrum slender, reaching almost to apex of third segment of first antenna, 
apex obtuse; carinae sharp, carried well back on to carapace; lateral carinae 
sharp, not ending in a rounded boss. 
Squame of each second antenna long and very slender; terminal spine long, 
slender and sharp. Interantennal spine small and slender, semi-pyramidal. 
Median arch of upper lip smooth. Eyes small. 
Carapace higher than broad, twice as long as broad, shorter than abdomen. 
Cervical suture deeply impressed rounded; branchio-cardiac grooves feebly 
impressed, areola broad. Branchiostegites and anterior of carapace studded 
with numerous minute tubercles. 
Sternal keel broad and blunt between second and third pereopods, high, 
slender and sharp between first and second pereopods. Lateral margins of 
lateral processes between second pereopods sharp; processes between third 
pereopods obliquely flattened, upper margin sharp; sternal keel continued 
across as an obsolete carina. Processes between fourth pereopods short and 
slender, upper margins sharp. 
Telson entirely calcareous, with a spine on each lateral margin at apical 
third; inner rami of uropods each divided by a longitudinal median carina, 
ending in a sharp spine near posterior margin; outer rami each divided by 
two longitudinal median carinae, inner carina continued across the transverse 
suture, ending spineless at posterior margin, the transverse suture placed at 
the apical third, several sharp spines along the suture; a sharp spine at centre 
of outer lateral margin of each ramus. 
Pereopods slender. 
Great chelae long and slender. Propodus three times as long as broad ; 
upper margin smooth, lower margin smooth, apex sharp, cutting edge 
smooth or with two or three small tubercles. Dactylus slender, upper margin 
smooth, cutting edge smooth or with a few small tubercles, apex blunt. Upper 
margin of carpus smooth ; upper margin of merus with one short sharp spine. 
Habitat. — Victoria: Bunyip (D. J. Mahony). 
Type in the National Museum, Melbourne. 
