NARRATIVE OF THE CRUISE. 



149 



altered habits from those of their congeners, and live in different media, usually have an 

 accelerated embryological development, because the medium necessary for the early stages 

 of the larvae has been relinquished by the parent. Crabs are known to live in three 

 media, — in the sea, in fresh water, and on the shore. The mode of propagation of the sea 

 crabs, passing through a zoea stage, must be considered their normal way of develop- 

 ment. In Telphusa — as I discovered after carefully investigating these freshwater 

 crabs in the mountains of Italy — the newly hatched young ones remain attached to 

 the abdomen of their mother. They have no metamorphosis, and as their mode of lift; 



Fig. 61. — Cedar Avenue, Hamilton, Bermuda. (From a Photograph.) 



has many resemblances to that of the Grrqosus found here, one may fairty conjecture that 

 in tins Crab also no metamorphosis occurs. 



" The Mangrove swamp is a hot and damp place, especially favourable for tropical 

 animal life. Large Dragon-flies (Libellula and Agrion) fly about, and a little Cicindela is 

 perpetually flitting from one place to another, and many other insects can be captured. 

 Under stones two specimens of another land crab were procured, which evidently belongs 

 to the Telphusidse, the freshwater crabs, and comes nearest to the genus Boscia, found in 

 Brazil and South America, from which it differs, however, in some slight respects. There 

 was no fresh water near the place where I found the specimens. With regard to its 

 habits, it is far from having the agility of the Grapsus, is easily caught, and seems to 

 live in holes under stones. Some specimens of Ocypoda rhombea and Gecarciniti 



