128 BULLETIN OF THE BUREAU OF FISHERIES. 
Piate LILI. 
Fig. 31. Dorsal view of adult female crab. 
Fig. 32. Ventral view of immature female crab, with triangular abdomen. 
Fig. 33. Ventral view of adult female crab, with broad abdomen. 
Puate LIV. 
Fig. 34. Dorsal view of adult male crab. 
Fig. 35. Ventral view of adult male crab. 
Fig. 36. Crate containing adult crabs for observation. It measured 2 by 2 by 4 feet and consisted 
of an iron frame covered with chicken wire fencing with a 1-inch mesh. It was divided into four 
vertical compartments to prevent the crabs crowding together and to prevent the escape of all the crabs 
in case the wire was torn at any point. A wire bail was attached at each end and brought together 
over the topin the middle. To their point of union a wire was secured by which the crate was lowered 
and raised. 
Piate LV. 
Fig. 37. Type of float which was used in the experiments with adult crabs. 
Fig. 38. Wire cages in which molting crabs were confined for observation. The cages rested on 
the bottom within the inclosure shown in figure 20, each being raised and lowered by means of an indi- 
vidual wire, the upper end of which was attached to a post at a point above high-water mark. 
