Nakkativ?: of Bahama Expedition. 97 



anchorage, but near the mouth of the bay, while on a trip for 

 turtles, Cicindcla torfiiosa and C. olivacea were both taken. 



" Spiders were tolerably numerous, the Attid^ forming a 

 conspicuous feature among them. A few Lepidoptera, chiefly 

 micros, were taken on a little island in the bay." 



The most interesting crustaceans were the land-crabs. A 

 large species of Geocarcinus, common here, is of a bluish 

 grey color, and esteemed a delicacy by the natives. 



The modifications of the crustacean anatomy, to subserve 

 the purposes of an essentially terrestrial life, form an interest- 

 ing study. The whole structure connected with respiration is 

 specialized for the purpose of making a little water go a long 

 way. Externally we notice the unusally hard and dense shell 

 covering the gill-chamber. Below, the branchial region is 

 covered with a dense spongy mass of matted hairs, excellently 

 adapted to the retention of moisture, and preventing evapora- 

 tion through the carapace. The openings around the maxil- 

 lipeds are lined with similar hairy brushes for the same pur- 

 pose. Opening the branchial chamber, we find it lined with 

 a thick, smooth membrane bearing in texture a remarkable 

 resemblance to India-rubber, and apparently just as impervi- 

 ous to water. The eight pairs of gills are stiff and erect, and 

 do not collapse or mat together when out of the water, as do 

 those of ordinary crabs. A beautiful contrivance exists for 

 keeping these structures moist so long as even a little water 

 remains in the bottom of the branchial chamber. Attached to 

 the third maxilliped is a long thin curved plate bearing a 

 brushy fringe on its edge. This plate is directed backward 

 and fitted perfectly over the outer surfaces of the gills, so 

 that the animal, b}' a motion of the maxilliped. can dip this 

 curved brush in the water at the bottom of the branchial 

 chamber, and apply it in the most effective manner to the 

 outer surfaces of all the gills. On the inner surfaces of the 

 gills two smaller brushes similarly arranged serve to apply the 

 water. These inner brushes are attached to, and worked by, 

 the second and third maxillipeds, the larger of the two being 

 attached to the first, and the smaller to the second maxilliped. 



