VARIATION AND ZOOGEOGRAPHY OF LIGUUS IN FLORIDA. 451 



* pink peripheral line is present, as in western Florida. The aeries is part ieularly 

 interesting because of the minor modifications which give an individuality to 

 the forms of each key. Incipient races have evolved from the original stock 

 the formation of channels having cut the former area into keys isolating the 

 colonies. Big Palo Alto, the last to be dismembered from Largo, received I 

 tincture of the castaneozonatus stock, which came too late to reach the key* 

 further north. The spreading of roseatus northward was arrested by the d p 

 Caesar's creek, flowing between Old Rhodes and Elliott's Key, which was prob- 

 ably established before the other and shallower channels. The saluttt features 

 of these colonies of roseatus are as follows: 



1. Roseatus with colors like those of the Largo hybrid race, Pumpkin Ke\ 



2. Like No. 3, but with a small admixture of castaneozomht*, Big Palo Alto 



Key. 



3. Ground white, inclining to rose; spire extensively pink; a pink subsutural 

 and yellow peripheral line. Shell larger, Totten's Key. Shell smaller, Little 



Palo Alto Key. 



4. Ground largely yellow in two broad zones, spire extensively pink. 



(a) Zones deep yellow; peripheral line pink or pinkish yellow. Porgy I t\ 

 (6) Zones pale yellow; peripheral line very faint or wanting, Old Rhodes I ey 

 (c) Zones faint yellow, wanting on the last whorl, Adams Key. 

 Pumpkin Key. 40 specimens taken by Mr. Moore in 1904 are chiefly 

 (75 per cent) yellow tinted on the last half whorl, with several gr< m lii a or 

 none above the periphery, and numerous wider yellow bands below. Others 

 (25 per cent) are pinkish-white with very faint lines only; but several of them 

 have added a yellow edge 5 to 8 mm. wide, to the lip. In all, the sutural line is 

 wanting or weak. A yellow peripheral line is visible in about half of them. 

 They are more like Largo roseatus than like the following lots, but in a ries of 

 40 there are none of the dark-zoned or crenatus forms. These roseatus differ 

 from those of the West Coast in the thinner shell and columella. The latter if 

 either continuous or truncated at the base. In young shells the columcllar trun 

 cation is generally much more distinct and the axis itself is b i\ ier. They arc 

 like West Coast roseatus, while the later stage diverges. 



Totten's Key (PL XXXVIII, figs. 18, 18a). The shells are rosy white with 

 a large part of the spire beautiful rose color. The last third or half of a whorl i 

 pale yellow, following a growth-arrest (fig. 18a). When the change comes later, 

 the vellow is the more marked (fig. 18). In every one of the 43 specimens, the 

 peripheral belt is visible, and it is usually quite conspicuous and bright yellow. 

 In two shells it is pink. A narrow pink sutural line is invariable. About 60 

 per cent of the shells have no greenish lines, and these are numerous on only about 

 10 per cent. The usual length is about 50 mm., but the largest is 58 mm. long. 

 Little Palo Alto Key. The specimens are entirely similar, except that they 



average smaller than those of Totten's Key. 



Porgy Key (PL XXXVIII, figs. 19, 19a). 25 specimens collected by Mr. 



