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long tendril-like feet which do not serve for locomotion, but 
keep up a constant sweeping niotif^n by which they bring food 
particles into the mouth. Leaving out certain parasitic forms 
there are two families of them, the Stalked Barnacles {Lcpadidae ) 
and the Stalk-less ones {Balamdae), The Stalked Barnacles 
include forms like Lepas which are often found on the bottom of 
ships and on floating timber. The Acorn Barnacles ( Baitutus 
and other genera) which are so common on rocks between 
tidnl marks, belon«; to the second group. 
KING CRABS (Gigantostraca). 
The Gigantostraca or King Crabs include a single genus, 
IJmnlus- It is usual to place them after the Crustacea, although 
their relationship with the latter is only a slight one. Not- 
withstanding the fact that they are aquatic and breathe by 
means of gills, they seem to stand nearer to the Spiders and 
Scorpions. Their nearest allies were the Trilobites which 
flourished during the Palaeozoic epoch and are amongst the 
earliest known fossils. There is a striking resemblance between 
the larva of the King Crab and the Trilobite, so that that parti- 
cular stage has been called the Trilobite stage. 
Seen from above the King Crab shows three sections : a 
huge round shield covering the cephalothorax ; a smaller hexa- 
gonal shield covering the abdomen, carrying six movable 
spines at either side ; and the long spike-like tail The tail 
serves only the function of lever when the animal wishes to 
turn over. Seen from below the animal shows in the region of 
the cephalothorax a pair of nippers in front of the mouth, five 
pairs of walking legs, and a plate-like pair of limbs, the oper- 
culum, which covers the five leaf-like pairs of abdominal 
appendages. These leaf-like feet serve the double purpose ol 
swimming and breathing. 
The species which occurs Is these seas in the Moluccan 
King-Crab {Limulus moluccaniis). Other species are found in 
Chinese and Japanese waters and off the East Coast of the 
United States. 
