HOMARUS AND NEPHROPS. 



259 



fuUy developed pleurobranchife. Moreover, the bran- 

 chial filaments of these gills are much stifFer and more 

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

 portant distinction is presented by the podobranchite, in 

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

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



Fig. 68. 'Pod.ohrameh.ise^oi A, Parastacug ; 'B, Ncphrops ; G, Palo'moii. 

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

 ment ; al, wing-like expansion of the stem ; h, base ; hi\ branchial 

 filaments ; ep, epipodite ; I, branchial laminee ; 2>^> plume ; st, stem. 



corresponding with the lamina of the crayfish gill, and the 

 other {])T) with its plume. Hence the base (fc) of the 

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

 is continued into a broad ej)ipoditic plate {ep) slightly 

 folded upon itself longitudinally but not plaited, as in the 

 crayfish. 



The Norway Lobster {Nephrops norvec/icus, fig. 69) 



