32 AUSTRALIAN FRESHWATER AND LAND CRAYFISHES 
Squame of each second antenna slender, terminal spine short and sharp. 
Interantennal spine short and broad, apex sharp, lateral margins rather sharp. 
Carapace shorter than abdomen, broader than high, densely punctate; 
branchio-cardiac grooves obsolete, areola very broad ; four or five small sharp 
spines along anterior of branchiostegites below the cervical groove. 
Tel son with a small sharp spine on each lateral margin at posterior third; 
posterior third of telson membranous. Uropods longer than telson; inner 
rami each divided by a longitudinal median carina, ending in a small sharp 
spine at membranous junction, a spine on each outer lateral margin at middle, 
posterior half of each ramus membranous. Outer rami each divided at apical 
third by a transverse suture, numerous small sharp spines along the suture, 
posterior two-thirds of each ramus membranous. Lobes at base of uropods 
with upper and lower lobes produced to a small sharp spine. 
Sternal keel high, very slender and sharp. First two pairs of lateral 
processes small and sharp, third pair larger, sharp ; fourth pair large, concave, 
each with a small round opening on outer lateral surface, lateral margins 
sharp; processes between fourth pereopods short, upper surface concave, 
lateral margins sharp. 
Great chelae stout, with a few scattered small punctures ; propodus twice as 
long as broad, upper margin serrated, lower margin smooth, four or five small 
tubercles along cutting edge; dactylus stout, upper margin smooth, one or 
two small tubercles along the cutting edge. Carpus with three sharp spines 
along upper margin and a row of small tubercles on upper surface below 
the spines, a small spine at anterior margin, surface of carpus punctate. 
Merus with one large sharp spine and several small tubercles along the upper 
margin. 
Habitat . — Wessell Island, Japanese Creek (C. Barrett). 
This species is based on a single specimen obtained by Mr. 
Charles Barrett from the Wessell Island, which is situated 
N.W. of the Gulf of Carpentaria, 30 miles from the coast of 
the Northern Territory. The distinctive characters, however, 
remove any doubt as to the specimen being an aberrant form 
of any known species. 
In the number of carinae on the carapace harretti resembles 
C. hicarinatus (Gray) (6), which was described from speci- 
mens collected at Port Essington; Gray’s species has not 
since been recorded from the north, but it is common in the 
south-west of Western Australia. The types of hicarinatus 
were examined for a previous paper (2) and found identical 
with G. intermedins Smith (12), the types of which are in the 
National Museum, Melbourne. G. harretti and hicarinatus 
may be separated by the form of the rostrmn, sternal keel and 
great chelae. 
The only other species known from the north coast of 
Australia is G. quadricarinatus (von Martens) (14). The 
number of carinae on the carapace immediately separates 
quadricarinatus and harretti ; other important differences are 
found in the form of the great chelae and the sternal keel. 
