390 



ANNUAL REPORT SMITHSONIAN INSTITUTION, 1917. 



ANIMAL LIFE. 



It is impossible within the scope of this paper to give a detailed 

 account of the animals of Royal Palm State Park. The insect 

 fauna alone must certainly include thousands of species, only a few 

 of which can here be mentioned. 



The tree snails (see pi. 35) which form such an attractive feature 

 of the forest, though varying greatly in color, are referred by zoolo- 

 gists to a single species, Liguus fasciatus. These beautiful creatures, 

 which spend their lives on the trunks of trees browsing upon micro- 

 scopic cryptogamous plants, are air-breathing mollusks like their 

 relatives the common snails, having their eyes on the ends of long 

 tentacles (fig. 12) which they can fold in like the tip of a glove 

 finger. Specimens sent by Mr. Mosier from Paradise Key are 

 now domesticated in one of the greenhouses of 

 the United States Department of Agriculture, 

 having borne the trip from their native forest 

 without apparent inconvenience. As in allied 

 genera these animals have both sexes united in a 

 single individual; so that each may become both 

 a father and a mother. In mating they do not 

 appear to discriminate as to color, for a pure 

 white-shelled form vavij be seen paired with one 

 which is yellow-banded or mottled like tortoise 

 shell. They sometimes fall victims to another 

 air-breathing mollusk, the cannibal snail, Glan- 

 dina truncata (pi. 26, fig. 2), the young of which, 

 sometimes devour one another. 



Other snails of this family are the minute 

 Polygyra septernvolva (pi. 36, fig. 3) and P. 

 uvulifera (pi. 36, fig. 4) with flattened shells 

 composed of many whorls coiled like a watch spring. Another lit- 

 tle shell, Uelicma orUculata (pi. 36, fig. 5), is distinguished by hav- 

 ing a little door, or " operculum," with which it closes the orifice of 

 its shell. Among the pond snails are Plcnnorhis duryi (pi. 3, fig. 6) 

 and Physa gyrina (pi. 36, fig. 7), the latter with a thin polished, 

 left-handed shell. 



The great marsh snail, Ampullaria depressa^ is of interest as the 

 principal food staple of the Everglade kite, already mentioned. The 

 colored illustration in the center of plate 35 was made from a 

 living specimen sent to Washington from Royal Palm State Park. 

 Its eggs, resembling flesh-colored pearls, are attached to the stems 

 of water plants (fig. 13). Last of all must be mentioned the little 

 bivalve, Musculum partumeium (pi. 36, fig. 9), which has a thin, 

 orbicular shell through which its pulsating heart can be seen. It is 



Fig. 12. — Tree snail 

 OF Royal Palm 

 ParKj Liguus fas- 

 ciatus, WITH EGG. 

 Both sexe.s ake 

 united in each in- 

 DIVIDUAL. Nat. size, 



