14 
REVISION OF THE GENUS EUASTACUS 
Second antennae reaching fourth abdominal segment. Squame smooth, 
inner lobe very short and broad, terminal spine long and stout, sharp. Inter- 
antennal spine large, triangular, apex blunt, lateral margins serrated. 
Carapace more than twice as long as broad, broader than high, longer 
than abdomen. Branchiostegites studded with numerous small tubercles; 
several sharp spines and a few large tubercles in irregular rows on upper 
margin. 
Abdomen spinose. First segment with a long stout sharp spine on each 
lateral lobe, a short stout blunt spine above each lateral spine. Second segment 
with two short slender sharp spines on each lateral margin; a long sharp 
spine, very large at the base, and a short sharp spine very broad at the base, 
directed slightly forward, above the lateral spines. Third segment with a 
slender sharp spine at each lateral margin ; a long sharp spine, very large at 
the base, and a short sharp spine, very large at the base, above each lateral 
spine. Fourth and fifth segments each with a long slender sharp spine at each 
lateral margin; a short broad sharp spine, a long sharp spine very broad at 
the base, and a short sharp spine very broad at the base, above each lateral 
spine. Sixth segment with a very short broad sharp spine near each lateral 
margin, a very short broad sharp spine above each lateral spine. 
Telson broad, slightly longer than broad, almost completely divided by a 
transverse suture, with a spine on each lateral margin at suture, and three or 
four small spines on surface; inner rami of uropods each with a spine on 
lateral margin near posterior margin, two or three small sharp spines along 
outer lateral margin; outer rami of uropods each with numerous spines along 
the transverse suture, some examples with two or three small spines on outer 
lateral margin. Lobes at base of uropods without spines. 
Sternal keel broadly rounded between first and third pereopods, sharp 
below great chelae; first pair of lateral processes very small and sharp, second 
pair larger, third pair four times as large as first, rounded; posterior pair 
large, blunt, and deeply grooved; processes between fourth pereopods long 
and stout. 
Great chelae slender, propodus two and one-half times as long as broad, 
upper margin with four sharp spines, lower margin with two rows of large 
sharp spines posteriorly and a single row of smaller spines anteriorly, cutting 
edge with two large and several small tubercles, a few small tubercles on 
upper surface below base of dactylus; dactylus very stout, apex short and 
blunt, cutting edge with two large and several small tubercles, upper margin 
smooth, two or three small spines near apex. Carpus with two long sharp 
spines on upper margin, upper surface deeply grooved; merus with two large 
and five small sharp spines on upper margin. 
Habitat. — Victoria: Wahgunyah, Murray River; Cobram, Murray River 
(P. J. O’Connor); King River (M. Webb); Ovens River, Wangaratta; 
Dondangadale River; Buffalo River (E. Clark) ; King River. 
New South Wales: Hay, Murrumbidgee River (E. G. Austin); Narran- 
dera, Murrumbidgee River (L. C. Haines) ; Deniliquin, Edward River. 
South Australia: Blanche Town, Murray River (G. Brooks); Renmark, 
Murray River (M. Kennewell) ; Morgan, Murray River (Sth. Austrl. Mus.) ; 
Mannum, Murray River. 
Eeadily separated from E. elongatus sp. nov., by the large 
stout chelae, the more spinose telson and uropods; and the 
structure and size of the abdominal spines; the larger and 
