AKT. 20 FLORIDA TREE SNAILS SIMPSON 7 



on the rocky ridge of the lower mainland. Hammocks began to 

 be developed in protected places on this ridge, and conditions were 

 right for the establishment of colonies of Liguus on the soil of the 

 United States. 



We can not tell whether the first successful settlement of these 

 snails was made on the great southwest key or southeast mainland, 

 but quite likely on the former. A gravid specimen of a form close to 

 our present grapMcus clinging to the tree on which it had made its 

 home was thrown up on this island, either by an unusually high 

 tide or during a hurricane. It probably came from somewhere in 

 the neighborhood of Cabanas, about 40 miles west of Habana, where 

 Dr. Carlos de la Torre, the late John B. Henderson, George H. 

 Clapp, and the writer found a form of Liguus in considerable num- 

 bers that has nearly all the characters of that beautiful snail. It is, 

 however, smaller, is a richer yellow, is not quite so porcellanous, and 

 is a little less flamed on the spire. I have little doubt that our 

 gra'phicus sprang from the same stock as the small Cuban form did. 



The newly arrived snail multiplied and probably spread over most 

 of the drier parts of the island, for at least recognizable fragments 

 of it has been found on most of the keys where there is high land. 

 Certain forms among its progeny seem to have partially lost their 

 coloring, and one of these which Say called solidus has a broad, 

 faint, spiral yellowish band above the periphery and another on the 

 base. A second somewhat thin variety which has delicate coloring 

 Pilsbry has named solidulus. This is whitish or cream colored with 

 one or two faint yellowish narrow, spiral lines at the periphery, 

 another at the suture, and sometimes a broad one on the base. Some 

 of the shells which are doubtless of this variety have two or more 

 narrow greenish or bronzy spiral lines on the last whorl, and others 

 scarcely show a trace of banding. A shell from Ramrod Key of 

 the lower islands is almost pure white throughout, and a very solid 

 form which I found on Big Pine Key is ivory white, with a single 

 narrow, bronzy peripheral line and a decidedly truncated columella 

 to which I gave the subspecific name of crassus. Mr. John B. 

 Henderson had specimens in his collection from Key West which I 

 refer to this. I feel sure that if a large collection of solidus could 

 have been made from the Lower Keys it would have shown a 

 considerable amount of variation in coloring. 



Reeve bestowed the name Achatina picta on a form of solidus 

 which has a pale, ashy yellow ground pattern with longitudinal 

 bluish smears and a double row of squarish brown spots at the 

 periphery and sutures, and he gave Cuba as a locality for his shell. 

 There is a specimen in the collection of the United States National 

 Museum with the same locality given, and many years ago I re- 



