186 VARIATION, DISTRIBUTION, AND EVOLUTION OF THE GENUS PARTULA. 
impressed, sometimes faintly marginated; lip narrowly thickened, occasionally connected 
with the columella by a thin callosity; columella dentate. Color light or dark chestnut 
brown, sometimes striped with darker or wholly of a straw color. 
““Var. Encircled with three dark reddish brown bands, on middle of last whorl, at the 
umbilicus, and just beneath the suture. 
*“Obs. The above species is allied to P. otaheitana. It is, however, smaller and less 
elongate. 
“Dim. Long. 16, diam. 9 mill. Hab. Tahiti.” 
In his invaluable monograph, Garrett gives the following account of affinis: 
“‘Pease’s affinis, which can not be separated from some of the small abbreviated forms 
of Otaheitana, occurs in greater or less abundance in all the valleys from Haona as far as 
the southeast end of Taiarapu peninsula, and round the opposite coast as far as Papier 
[Papeari] on the southwest of Tahiti proper. In Papinoo [Papenoo] I discovered a large 
colony of affinis, many of which had the pinky flesh-colored lip and sinistral form of Otaher- 
tana. Far up in the same valley, though common, none but dextral forms were found, and 
out of thousands taken in the other valleys, not one sinistral example occurred to my notice. 
In a valley several miles from Papinoo I found a small colony of affinis, which were marked 
by three transverse reddish chestnut bands like lignaria. And, most singular, no other 
banded specimens of affinis occurred to my notice in any other part of the island. It is 
the variety dubia Pse., and by Carpenter erroneously referred to varia.” 
In the detailed analysis of the variation and distribution of affinis, as this will 
be presented in the following pages, it will be made evident that, in the main, the 
situation so clearly and precisely described by Garrett exists to-day, but it will also 
be demonstrated that certain changes have taken place since Garrett’s observations 
were made. Some of these changes are sufficiently important to be noted at this 
juncture. 
Garrett speaks of a large (local) colony of afinis in Papenoo Valley whose 
members were sinistral and were colored in certain respects like rubescens; in my 
own collections only 7 snails out of 160 adults of this variety were reversed, 
even though three separate journeys were made into this valley in as many different 
years; these, however, were brown, not yellow or red. In his very next sentence he 
says that not a single sinistral example was secured elsewhere, out of thousands 
collected. In my personal experience, such individuals were discovered in six other 
valleys, in widely separated parts of the whole range. Again, Garrett locates a 
banded variety, which apparently was named P. dubia by Pease, in a valley “several 
miles from Papenoo,” adding that no other banded specimens were found elsewhere 
in the island. In a personal letter to Hartman, he specifies the exact distance of 
8 miles beyond Papenoo for the locus of dubia which my own observations have con- 
firmed. But it is significant, in view of what Garrett says, that banded forms of 
one kind or another were collected by me in twenty-one different valleys, located in 
various parts of the whole range! As we can not believe that Garrett was unac- 
quainted with the snails of many, even if not of all, of these valleys, it is evident 
that a notable development of banded types has occurred since his day, even as in 
the case of occasional sinistral individuals. 
