Narrative of Bahama Expedition. 125 



which comes in contact with the propodite. By the normal 

 motion of the hand this fringe is made to sweep across the 

 inner surface of the propodite. There seems to be much more 

 than the usual freedom of motion between the carpus and the 

 hand. When the cheliped is folded or the fingers brought to 

 the mouth, the spine lies snugly between the hand and the 

 meros. The whole contrivance is so evidently adaptive that 

 one naturally seeks an explanation of the intent of the struc- 

 ture, but I know' of no purpose unless it be defensive, and that 

 explanation does not seem entirely satisfactory. When the 

 cheliped is extended, the long carpal spine projects at nearly 

 a right angle with the hand. Another conspicuous character 

 of this species is the long spine arising from the side of the 

 carapace. Perhaps the largest of the Cancroid group secured 

 at the Tortugas was a specimen of Achclons spinimanus Latr.. 

 which has a spread of about eleven inches. The manus is 

 conspicuously striped brown and buffy, and the fingers or 

 claws armed with prominent nodules throughout the length of 

 their opposed surfaces. 



Among the Ocypodoidea are the familiar Ocypoda arciiaria 

 (Catesby) and the brightly colored land-crab Gcocarciniis 

 lateralis (Frem.), which is almost alwa}'S in evidence on the 

 larger islands of the Tortugas group, scuttling around among 

 the dried grass and leaves, and assuming belligerent attitudes 

 when approached, reminding one of very large "fiddler" 

 crabs. These are among the most conspicuously colored of 

 all the crabs secured during the cruise, the chelipeds and dor- 

 sal surface being really beautiful in their liver \- of yellow, and 

 brilliant crimson shading into pink and black. Their life is 

 almost exclusively terrestrial, and the}' seem to have few 

 enemies, at least on these islands. That the\' are efhcient 

 scavengers was proved by the facility with which the\' cleaned 

 the skeletons of two large turtles left on I5ird Key for that 

 purpose. Several specimens of a tortoise crab, Calappa iiiar- 

 morata Fabr. were found near Garden Key. and caused con- 

 siderable amusement by their peculiar habit of spouting ii little 

 fountain of water almost directh' upward, the mouth-parts 



