REVISION OF THE GENUS EUASTACUS 
21 
Astacus nobilis (Dana), von Martens, Monatsber. Akad. Wiss. Berlin, p. 
616, 1868. 
Astasopsis nobilis (Dana), Haswell, Cat. Austrl. Mus., Crust., 1882, p. 175; 
Faxon, Proc. U.S. Nat. Mus., xx, p. 675, 1898; Faxon, Mem. Mus. 
Comp. Zook, xl, 8, 1914, p. 402. 
Astacopsis serrafus (Shaw), Smith, Proc. Zook Soc. Lond., p. 157, 1912; 
McCulloch, Rec. Austrl. Mus., no. 11, p. 237, 1911. 
Euastacus nobilis (Dana), Clark, Mem. Nat. Mus. Viet., x, 1936, p. 15, pk 
iii, fig. 15; Clark, Viet. Year-Book, 1936-37, p. 35. 
Astacopsis kershaun Smith, Proc. Zook Soc. Loud., 1912, p. 160, pk xix. 
Euastacus nobilis s. sp. kershaivi (Smith), Clark, Mem. Nat. Mus. Viet., 
X, 1936, p. 16, pk iii, fig. 16; Clark, Viet. Year-Book, 1936-37, p. 35. 
Length of average adult specimen 263 mm. 
Rostrum broad, reaching base of third segment of second antennae, apex 
long, slender and sharp; lateral carinae obtuse, continued well back on to 
carapace, punctate, each wdth one large tubercle at apex, and two or three 
smaller tubercles posterior to it. A blunt, punctate carina, and a large 
rounded boss with a small tubercle, posterior-laterally to it. 
Second antennae reaching fourth abdominal segment. Squame smooth, 
inner lobe broad, terminal spine long, slender and sharp. Interantennal 
spine broadly triangular. 
Carapace more than twice as long as broad, broader than high, as long 
as abdomen. Branchiostegites spar.sely studded with small tubercles, two 
or three small blunt spines anteriorly on each branchiostegite below cervical 
groove, with or without larger tubercles along the dorsum of each branchio- 
stegite. Entire carapace sparsely punctate. 
Abdomen spinose and tuberculate. First segment with a long sharp 
spine on each lateral lobe. Second segment with three long slender sharp 
spines at each lateral margin, a large sharp spine above the lateral spines, 
and a very large rounded boss above these spines. Third and fourth 
segments each with a long stout sharp spine at each lateral margin ; a very 
slender long sharp spine and a broad sharp spine above the lateral spines, 
and a very large rounded boss above these spines, much smaller on fourth 
segment. Fifth segment with a long stout sharp spine at each lateral margin, 
two slender sharp spines above the lateral spines. Sixth segment with a 
small sharp spine near each lateral margin, and a small sharp spine above it. 
Telson long and broad, with a long, slender sharp spine on each lateral 
margin at the transverse suture, several short sharp spines on upper surface. 
Uropods longer than telson ; inner rami each with three or four short sharp 
spines along the outer lateral margin, median carina very feeble, ending in 
a small sharp spine near the posterior margin, two small sharp spines along 
the carina; outer rami each with a spine on outer lateral margin at the 
transverse suture, numerous very small spines along the suture. Lobes at 
base of uropods with upper lobe produced to a very short sharp spine. 
Sternal keel moderately sharp; lateral processes large and moderately 
sharp, processes between third pereopods very large and deeply grooved ; 
processes between fourth pereopods long and slender. 
Great chelae short and stout, propodus more than twice as long as broad, 
upper margin with four sharp spines, lower margin with two rows of widely 
separated short sharp spines, apex sharp, cutting edge with two large and 
several small tubercles, a broad sharp spine on upper surface near base of 
cutting edge, another sharp spine at base of dactylus ; a few small tubercles 
