8 
REVISION OF THE GENUS EUASTACUS 
stated to be Astacus serratus Shaw, the reasons for the 
alteration shown above are given on page 11. 
Crayfishes of the genus Euastacus are characterized by 
their large size and the armature of spines and tubercles on 
the carapace, abdomen and legs. They have been found in 
most of the rivers of Victoria; in the south-east of South 
Australia ; and in the coastwise rivers of New South Wales 
and Queensland as far north as Coen. One species, Astacopsis 
austj'alasiensis (Milne-Edwards), was recorded in 1903 from 
Sorong in the north-west of New Guinea (27), but the genus 
has not otherwise been recorded from any locality outside the 
mainland of Australia. 
Prior to 1936, eleven species of spiny-tailed crayfishes, now 
included in the genus Euastacus, had been described; these, 
with type locality and the date of description are : 
Cancer serratus Shaw (28), New Holland, 1794. 
Astacus australasiensis Milne-Edwards (20), New Holland 
(later given as Sydney), 1837. 
Astacoides nobilis Dana (4), ? New South Wales, 18.52. 
Astacoides spinifer Heller (13), New Holland, 1865. 
Astacus armatus von Martens (31), Murray River, Aus- 
tralia, 1866. 
Astacopsis paramatteyisis Spence-Bate (30), Paramatta 
River, Sydney, Australia, 1888. 
Astacopsis si/dncycnsis Spence-Bate (30), Sydney, Aus- 
tralia, 1888. 
Astacopsis serratus var. yarraensis McCoy (18), Yarra 
River, Victoria, 1888. 
Astacopsis serratus var. hirsutus McCulloch (19), Belle- 
more Falls, Kangaroo River, New South Wales, 1917. 
Astacopsis kershawi Smith (29), Moe River, Victoria, 1912. 
Astacopsis feckeri Watson (33), Root’s Creek, North 
Queensland, 1935. 
Since these species were described, much doubt has been 
thrown on their identity and validity, most authors recog- 
nizing only one species, Astacus serratus (Shaw), as valid, 
while others included also Astacoides nobilis Dana. 
In the following pages the history of each of the names is 
given ; six of them are accejited as valid species, five are shown 
to be synonyms, and the two varieties are raised to full specific 
rank ; with the addition of three new species described herein 
the genus now has a total of nine species. 
Cancer serratus Shaw was described in 1794, and the 
description was accompanied by a large coloured figure. Since 
