VARIATION AND ZOOGEOGRAPHY OF LIGUUS IN FLORIDA 



inhabiting the whole tropical and subtropical region. Also by the absence of 

 fossil forms of the group in any other region. Two genera of Orthalieina range 

 outside of South America: Oxystyla, from southern Brazil to northern Mexico 

 and southern Florida, and Liguus in Haiti, Cuba and Florida. The Floridan 

 forms are in part identical with those of Cuba, in part different from any Cuban 

 races, though obviously of the Cuban Li guus fasciatus type. 



The Floridan land snail fauna associated with Liguus is in large part of 

 Cuban origin (Cuban species or groups). None of theee Cuban forms ha> • been 

 found in the Pliocene of southern Florida, which contains a varied fauna >f land 

 and freshwater mollusks. 



The foregoing among other considerations go to show that iguus retched 

 Florida from Cuba, and that it was probably a post-Pliocene immigrant. In 

 what manner its advent was made is not essential to the purposes of this ana} 

 but the transportation of living snails in holes or sealed to the bark of floating 

 trees, or of the eggs by hurricanes, suggest themselves. I have elsewhere given 

 reasons for attributing the Cuban element in the Floridan snail fauna to involun- 

 tary passengers whirled up into the air with Cuban forest d6bris, to be scattered 

 over sea and land along the Florida Strait. That act ual land connection between 

 Florida and Cuba existed as late as the life-time of 1 gum in 1 lorida seems im- 

 probable. The southern key region seems the most likely landing point of Liguus, 

 both because of its proximity to Cuba and because the present distribution of 

 races is most readily explicable by that hypothesis. 



By whatever means Liguus reached Florida, t he present Floridan forms arc 

 not a monophyletic group. They were not all derived from a singh introduction, 

 but are due to two or perhaps three importations. (1) Liguus crenatus is a 

 widely spread Cuban form, undoubtedly evolved in substantially its present 

 form before introduction into Florida. Reasons are given below for considering 

 it the first form introduced into Florida. (2) Liguus solidus of the southwestern 

 keys and Liguus fasciatus lignumvitce of Lignum Vita? Key possess much of the 

 color-pattern of typical Liguus fasciatus of Cuba, 3 though they have been modified 

 enough to be quite distinct from any existing Cuban race. These must be the 

 survivors of another importation of the L. fasciatus stock from Cuba. 



The Liguus fasciatus roseatus and L. /. castaneozonatus may have been deriv 1 

 from a third importation from Cuba, but it is at least as likely that these fori 

 evolved from the same fasciatus stock which gave rise to L./. lignumvike. If so, 

 the latter must have changed much less since the importation. No Cuban 

 forms closely resembling roseatus or castaneozonatus are known 



a Figures of varying forms of the typical race of Liguus fasciatus from Cuba may be seen in the 

 Manual of Conchology, XII, Plate LVII, figs. 70 to 74; Orbigny's Mollusques de l'ile d« < uba, Plate V I, 

 figs. 1, 2; Reeve's Conchologia Iconica, V, Achalina, Plate X, figs. 35a, b, c This tymeal form doe* 

 not exist in Florida. In Cuba Liguus fasciatus is widely spread, with numerous races and subspecies, 

 the distribution of which is very little known. It is hoped that the record so far as it still exists may 

 be preserved. The ceaseless destruction of Cuban forests for charcoal and clearing the land for 

 cultivation has already destroyed evidence which can never be recovered. 



4 1 figured a specimen of castaneozonatus said to be from Cuba in Manual of Conchology, HI, 



4 



