460 VARIATION AND ZOOGEOGRAPHY OF LIGUTJS IN FLORIDA 



Detroit, thirty miles south of Miami. Plate XXXIX, fig. 21. Collect H h 

 Professor J. W, Harshberger, August, 1911, and Mr. Morgan Hebard July iqi/ 

 Rather solid yellow crenatus with a pale or white peripheral band, white so' 

 and faint olivaceous lines on the last half whorl. The small series of 6 liv' ' 

 specimens is hardly sufficient to show whether this form occurs as a pure rac 

 I have provisionally included the Homestead and Detroit colonies in the Miami 

 series from their geographic position. The small number of shells seen is quite 

 insufficient to show the composition of the colonies. 



Key Largo. Collections were made by Mr. Moore at three points: near 

 Planter, not far from the south end of the Key ; back of Point Charles, and near 

 the north end of the island. Mr. Morgan Hebard took specimens at Largo Sta- 

 tion near the middle of the island. 



The chief characteristic of the key is the rich development of the chestnut- 

 black two-zoned race. The mixture of forms is otherwise as on the mainland 

 except that none of the " tortoise-shell ' ' form has been found. 



Two miles east of the town of Planter, near the south end of the key an 

 unselected series of 73 shells was taken by Mr. Moore in 1904. The thin, narrow 

 type of columella prevails in all of the color-forms, but some shells have the heavy, 



truncate type. 



1. Crenatus: white ground 34; diffuse yellow, often bright, the spire white, 14; 

 lines rather sparse, chiefly light olive; no colored subsutural line. Also three 

 specimens of the yellow form having roseate parietal wall but white apex and no 

 sutural line, thus uniting characters of crenatus and roseatus. 



2. Roseatus: Broadly two-banded with yellow, scattered lines and a sutural 



line olivaceous-yellow, 12. 



3. Castaneozonatus: With ground-pattern of the roseatus type, 10, of which 



four have broad blackish bands, the others imperfect bands. 



Largo Station, collected by Morgan Hebard. 12 specimens of the following 



forms: 



1. Crenatus, white with a few faint yellowish-olive lines on the base, 2 speci- 

 mens. , 



2. Roseatus, with a few yellow or pale green lines, 4 with two broad deep 

 yellow zones (PI. XXXIX, fig. 236), 3 with very pale yellow zones. 



3. Castaneozonatus, with zones like fig. 22a or with a few chestnut smears 

 only, in either case over a deep yellow-zoned ground, 2 specimens. M 



Hammock back of Point Charles, Key Largo, collected by Mr. C. B. ±vioo , 

 1904 (PL XXXIX, figs. 23, 23a). . that 



No crenatus in the series of about 80 shells. The roseatus form is JiKe ^ 

 from near Planter except in being larger. Castaneozonatus, figs. %>> ' 

 peculiar in that the dark band is almost unbroken on the early whorls, s ^^ 

 no trace of its origin as a series of longitudinal stripes or spots. 1 is ^^ 

 accelerated or evolved condition not found in any other colony. n y ugua jj y 

 proportion of the shells are broadly black-banded to the end, the ban 

 weakening on the last whorl or two. 



