196 A HISTORY OF RECENT CRUSTACEA 
times attaining a length of eighteen inches, and is valued 
for food, though it has a less delicate flavour than the lob- 
ster. Though its front legs make a very feeble show in 
comparison with the powerful chele of the lobster, when 
the mandibles are compared the advantage is greatly in 
favour of the Palinurus, or Crawfish as it is often called. 
Spence Bate has pointed out that in this genus and its 
immediate kindred there are button-shaped tubercles on 
either side of the trunk, which fit into cavities on the under 
surface of the carapace, and have a very great power of re- 
tention, this buttoning of the carapace being probably an 
important protection to the branchiz that are placed 
beneath it. Its long stiff antennz are said frequently to 
prevent it from entering the pots set for catching crabs 
and lobsters, and thus, while disappointing it in its search 
for food, indirectly help to save its life. As in Palinurus 
the ear-stones are introduced, and yet the animal has no 
claws with which to pick up grains of sand and place them 
in the auditory cavity at the base of the first antenne, it 
might well be wondered how the otoliths reach their de- 
stination; but Hensen explains that the crustacean has 
only to burrow with its head in the sand, and the required 
particles will easily find their way into the ear-chamber. 
| Palinosytus |, Spence Bate, 1888, has the rostrum an- 
teriorly produced so as to reach beyond the ocular segment, 
and by its connection with the segment belonging to the 
second antenne forms a channel for the protection of the 
ocular segment. ‘The first antennz have two short 
flagella, and their segment is not produced. beyond the 
extremity of the rostrum. ‘This genus belongs at present 
only to the southern hemisphere. A specimen of Palinosytus 
Lalandit (Lamarck), ten inches long, was taken by the 
Challenger near Tristan daCunha. Also a smail specimen, 
about an inch long, was taken near the Cape of Good Hope, 
and this in all but sexual character already appeared to 
have the perfect adult form. Palinosytus Hiigelii (Heller) 
is the common Crawfish of Sydney, in Australia, and if, as 
Haswell supposes, it be the same as the New Zealand 
Palinurus tumidus, Kirk, it must be credited with attaining 
