AUSTRALIAN MALACOSTRACOUS CRUSTACEA. 209 
Tribe ASTACIDEA. 
34. Astacopsis serratus (Shaw).—This animal has been given 
different. names by different naturalists, on account of some of 
them getting large and some small specimens. In large examples 
the abdominal somites are each armed with a row of strong 
conical spines, but in young specimens these are either rudi- 
mentary or quite absent. There are also other differences. It 
is distributed with some variation over most parts of New South . 
Wales. The colour, which also varies, is most commonly of a 
deep red. Attains a length of 18 in. Huxley mentions it in his 
book, ‘ The Crayfish,’ under the name of “ Australian Crayfish.”’ 
Tribe PEN IDEA. 
35. Peneus canaliculatus (Oliv.).—This is truly a handsome 
species, having, when alive, the most delicate tints, and sometimes 
growing to the great length (for a Prawn) of 10 in. It is one of 
the principal Prawns of the Sydney fish-market, but is not so 
common as its congener, P. esculentus. Port Jackson; Botany 
Bay; Japan. 
86. Peneus esculentus (Hasw.). — The common Prawn of 
Sydney, and caught in great numbers with the nets. This genus 
is remarkable for the large membranous appendage attached to 
the base of the first pleopod of the male, and called by Spence- 
Bate the “ petasma,” or curtain. In the female this appendage 
isquiterudimentary. Port Jackson; Port Darwin. Incidentally 
‘it might be mentioned that when the term ‘“‘ Prawn” is mentioned 
the genus Peneus is meant; Palemon, to which the English Prawn 
belongs, not being known here as an article of diet. 
Tribe CARIDEA. 
37. Rhynchocinetes typus (M.-Edw.).—This species surpasses 
in beauty any crustaceans that I have ever observed, the body 
being a beautiful semi-transparent tint, with here and there spots 
of light blue dotted over it. The chele are red with white dactyli. 
Altogether it is most disappointing to see their magnificent colours 
fade so much when the animals are preserved. They frequent 
semi-dark situations below low-tide mark, and if taken and put 
ina bottle containing sea-water die in a very short time, though 
: Zool. 4th ser. vol. II., May, 1898. P 
