4 PEOCEEDIlSrGS OF THE NATIONAL MUSEUM vol. 73 



animal becomes dormant, much as do those of northern countries 

 during hibernation, only the organs do not so completely cease to 

 function. Before the beginning of the rainy season, sometimes as 

 early as April, the snails dissolve or let go from this epiphragm, as 

 the gummy substance is called, and become active. Sometimes in 

 winter if there is rain and especially if the weather is warm they 

 do this but make an epiphragm and become dormant if it becomes 

 dry and cool again. 



They live, for the most part, on smooth trees, but sometimes they 

 are found on those with rough bark, even live oaks, and in our State, 

 only in its extreme lower part. Although almost wholly confined to 

 the drier hammocks in Florida I have collected them in our brackish 

 and fresh-water swamps, in the former on the tropical buttonwoods 

 iConocarpus) and on cypress trees in the latter. In very rare cases 

 they have been seen on Caribbean pine trees at the edge of ham- 

 mocks. Their food is the confervoid growth which is found on the 

 bark and possibly the leaves of the trees which they inhabit. Some- 

 times, especially during rain, I have seen them clinging to the 

 under surfaces of leaves though this was not for the purpose of 

 keeping dry. During the warm season they freely copulate, and 

 as they are hermaphrodites it is probable that nearly all the indi- 

 viduals become pregnant. 



In the warm or rainy season from May till November tremendous 

 showers fall in northern Cuba and trees in stream valleys bearing 

 colonies of Ligwus may be washed out and swiftly borne down on 

 the current of the mountain torrents and into the sea. It is probable 

 that most of our Ligims stock is derived from the northern slope of 

 western Cuba, and such trees thrown into the ocean are caught by a 

 small current that leaves the main stream which passes up the 

 Yucatan Channel, and this smaller flow hugs close to the northwest 

 shore of the great island. Farther on it joins the Gulf Stream after 

 the latter has passed entirely around the deeper part of the Gulf of 

 Mexico, the junction taking place in the Florida Strait, the whole 

 great current moving to the east and northeast and sweeping against 

 the lower part of Florida. This current in the strait moves onward 

 ordinarily at the rate of from 2 to 4 miles an hour, much depending 

 on the direction and force of the wind. In time of hurricanes with 

 wind and heavy rain from the west or southwest the speed of this 

 ocean river would be greatly accelerated, and trees bearing Liguus 

 might easily be borne from northwest Cuba to the keys in 48 hours. 



It is probable that some of the snails which adhere to the trees 

 on which they live may be carried high and dry on limbs during a 

 trip of considerable duration and distance as they are making this 

 passage, but even if they do become immersed for quite a length of 

 time I feel sure no damage would come to them. At one time I put a 



