MOUTH-PARTS OF THE SHORE CRAB. 141 
EXPLANATION OF THE PLATES. 
Plate 10. 
Fig. 1. A ventral view of a female of the Shore Crab (Carciims mcenas). On the left 
aide of the animal the first and second walking-legs ha>e been parted, to 
expose the approach to the inhalent opening between them, and on the right 
side the cheliped has been turned back to reveal as much as possible of the 
flange on the coxa of the third maxilliped, by which the inhaleut opening of 
Milne-Edwards is guarded. 
Fig. 2. The forepart of a similar view aftef the third maxillipeds have been divaricated, 
one of them cnt short beyond its basis, and the chelipeds removed with the 
exception of their coxse. 
Fig. 3. A ventral (posterior) view of the third maxilliped of the right side, removed from 
the body and flattened. Tlie dotted line i show the normal position of the 
epipodite. Tlie small drawing annexed shows a portion of the dorsal (anterior) 
surface of the ischium of the yellow appendage, enlarged. 
Fig. 4. A .similar view of the second maxilliped of the right side. 
Fig. 5. A similar view of the first maxilliped of the right side. 
Fig. 6. A similar view of the maxilla (second maxilla) of the right side. 
Fig. 7. A similar view of the maxillule (first maxilla) of the right side. 
Fig. 8. A similar view of the mandible of the riglit side. 
Fig. 9. A view of the mouth and of the structures arouud it, after removal of all the paired 
appendages save the maxillule and mandible of the right side. 
Fig. 10. A diagram of a transverse section through the branchiostegite and the structures 
which underlie it at the level of the articulation of the first walking-leg. 
Fig. 11. A diagram of a longitudinal section through the branchial chamber of the left side. 
The podobranch of the second maxilliped is shown in perspective, and the 
position of the arthrobranchs of the third ma-xillipeds is indicated in dotted lines. 
Fig. 12. A view of the Crab from the left side after removal of the branchiostegite. Part 
of the inner roof of the gill-chamber remains, and is held back by a hook above 
the third walking-leg. 
Fig. 13. A view from within of a portion of the removed branchiostegite of the same side. 
Fig. 14. A view from below of the inhalent openings above the first and second walking- 
legs of the same side. 
Fig. 15. A view from above of the gill-chamber of the same side. The portions of the inner 
roof which have not been removed are held back by hooks. 
Fig. 19. Portions of hairs from the third maxilliped : — A, from the median band of the 
ischium; B, from the palp of the same limb; C, from the tiagellum of the 
exopodite. 
« Plate 11. 
Fig. 16. A view similar to that iu Fig. 15, after the removal of the greater part of the giUs. 
Fig. 17. A similar view after complete removal of all the gills, save those of the second 
maxilliped, the third maxilliped being in the normal position. 
Fig. 18. A similar view with the third maxilliped divaricated from its fellow. 
