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TEANSACTIONS LLVERPOOL BIOLOGICAL SOCIETY. 



these modified limbs are enclosed within flap-like folding 

 doors. Many of the Isopods, although true water- 

 breathers, can live the greater part of their time on 

 land. Idothea baltica, shown at 1 (fig. XIV.), is com- 

 pletely aquatic, and lives on green and brown sea-weeds, 

 which it generally resembles closely in colour; while 

 Ligia oceanica (No 3) is found at or even above high tide 

 mark, generally hiding in crevices of the rock or between 



1 Idothea baltica. 2. Astacilla longicorms 3 Ligia oceanica. 

 1 3 



Pig. XIV., Isopoda (slightly enlarged). 



the stones of a pier during the day and coming out to run 

 about and feed at night. Astacilla longicornis (2) is of a 

 white colour, and can only be obtained from the deeper 

 water outside the bay by dredging. Our authority on 

 the Amphipods and Isopods and all higher Crustacea is 

 Mr. A. 0. Walker, F.L.S., a member of the Committee. 



The highest Crustacea, such as crabs and lobsters, 

 shrimps and prawns are known as Decapoda because they 



