HOMAEUS AND KEPHEOPS. 



259 



fuUy developed pleurobranchiee. Moreover, the bran- 

 chial filaments of these giUs are much stiffer and more 

 closely set than in most crayfishes. But the most im- 

 portant distinction is presented by the podobranchise, in 

 which the stem is, as it were, completely spHt into two 

 parts longitudinally (as in fig. 68, B) ; one half (ep) 



C st 



Fig. 68. PodobranchiEB of A, i'aj'a.steejts ; 'Q, Neplirops ; C, Palcsmmi. 

 A', C, transverse sections of A and C respectively, a, point of attach- 

 ment ; al, v^ing-like expansion of thfe stem ; S, base ; br, branchial 

 filaments ; ep, epipodite ; I, branoMal laminae ; pi, plume ; st, stem. 



corresponding with the lamina of the crayfish gill, and the 

 other (pT) with its plume. Hence the base (6) of the 

 podobranchia bears the gill in. front; while, behind, it 

 is continued into a broad epipoditic plate {ep) slightly 

 folded upon itself longitudinally but not plaited, as in the 

 crayfish. 



The Norway Lobster (Nephrops norvegicus, fig. 69) 



