454 VARIATION AND ZOOGEOGRAPHY OF LIGUTJS IN FLORIDA. 



a brown pattern of irregular oblong markings then appearing. The last V/ 2 

 whorls are white at suture, periphery and columella, elsewhere black with some 

 white spots, and bluish zones in the middle of the upper and lower surfaces. 

 The green lines of ordinary L. fasriatus are represented by obscure black lines. 

 The columella is white and either of the thick, straight and truncate typ 

 specimens) or of the thin, narrow type (2 specimens). 16 



Rabbit Key. Only dead shells, part of them retaining some color, were found. 

 They seem to be identical in all respects with the Chokoloskee hybrid race. 



4. Hybrid Colonies of Middle Cape Sable and the Southern-central 



Keys, segregating into roseatus, castaneozonatus, 



crenatus and marmoratus. 



Cape Sable, Middle Cape (PL XXXVIII, figs. 16, 16a-d). Two small lots 



taken by Mr. Moore in 1904. 



1. Thirteen crenatus (fig. 16d), yellow-tinted with light-green lines or white 

 with few pale lines or none (probably from loss of the cuticle and fading). All 

 of these shells are thin and rather small, length 40 to 45 mm. The columella 

 varies in both this and the next color-forms from thick and truncate to narrow. 



2. Twenty-one castaneozonatus similar to those of Cutler, the zones varying 

 from nearly continuous, fig. 166, to mere traces. Form rather capacious, length 

 42, diam. 24.5 mm., or more slender, length 41, diam. 22.5 mm. The suture has 

 a pale yellow marginal line or none, periphery with a similar narrow band or none. 

 The inner lip has purple vortex-stripes and a purplish brown or rose-brown outer 



stripe (PL XXXVIII, figs. 16, 16a, 6). 



3. Two "tortoise-shell" pattern similar to those of Cutler except that the 

 subsutural tessellation is less marked, the band being nearly continuous in one 



of them, fig. 16c. 



The hybrid race from this place does not differ materially from that of Cutler 



and adjacent localities on the east coast. 



Southern-central Keys. The group of keys comprising Duck, Grassy, Crawl, 

 Fat Deer, Vaca and their satellites, occupies a south-central position, and lies 

 between Matecumbe, etc., where only Liguus crenatus dwells, and the south 



western group of keys, upon which only Liguus solidus and its mutations 



It is somewhat remarkable that the prevalent races of Liguus upon these 



occur. 



south-central keys are related to those of Middle Cape Sable instead of to the 

 races of the keys on either side. The distribution of Oxystyla floridensistiso 

 suggests that there has been in the past a connection between the Cape Sab e 

 region and the southern keys closer than now exists. The faunal evi dence 

 points to a land connection, which now remains as extensive shoals within 



M While there is not the slightest ground for doubting Mr. McKinney's good faith, it see ™ s J ^ 

 that the four marmoratus in his lot were really shells which had been brought from Key a 



with the lot he was keeping for Mr. Moore, without 



foreign to Chokoloskee. 

 zonalus colonv. 



castaneo- 



