772 PROF. T. H. HUXLEY ON THE CLASSIFICATION [Julie 4, 



Fig. 7. 



1x24 



II*2i 





IV X 24 



^ al 



111 



Astacoides madagascariensis. 



I. The outer face of the podobranchia of the antepenultimate thoracic limb of 

 the left side ( X 2|). II. The inner face of the same : br, branchial fila- 

 ments. III. A transverse section of the middle of the podobranchia : st, 

 the grooved inner face of the stem. IV. The terminal hook of a branchial 

 filament ; and V. The apex of a coxopoditic seta. The straight line repre- 

 sents S fjs ? of an inch magnified to the same extent as these. 



