202 VARIATION, DISTRIBUTION, AND EVOLUTION OF THE GENUS PARTULA. 
In fecundity (table 138) there is nothing of note, but the data of heredity 
(table 138) are decidedly interesting. All of the young are unbanded, like the 
15 adolescents secured in this valley; possibly, therefore, the stripes are developed 
only late in life, but perhaps it is more likely that the dubia type is disappearing. 
Garrett speaks of a small colony of this form, but unfortunately he does not give a 
definite statement as to the presence of unbanded associates. Future studies of 
the colony will be most useful for the determination of this point. Finally it is 
important that the two young of reversed parents were also sinistral and that all of 
the young borne by dextral parents were directly coiled. None the less, snails of 
the former kind must be regarded as genetic relatives of the latter, for there are no 
other reversed affinis nearer than Papenoo, 8 miles away. 
Vault VALLEY. 
In this region a flourishing colony of affinis was found, although not a single 
adult or immature specimen of rubescens was taken. All but three of the full-grown 
shells are plain, and fall into light, medium, and dark groups (plate 29, figs. 42 to 44), 
but their comparison is relatively unimportant. The three banded shells (plate 29, 
figs. 45 to 47) are not dubia, but representatives of the other color-type, zonata, now 
met for the first time as such. The narrow median band of dubia is much broad- 
ened toward the right, and slightly to the left, while the sutural band is widened 
toward the sagittal plane of the shell, leaving only a narrow strip of the ground- 
color between it and the median element. The basal marking does not broaden 
to the same degree. 
TaBLe 139.—Partula otaheitana affinis. Vahii Valley. 
MEAN VALUE. 
Shell. Aperture. Length aper- 
Series. No. ture + length Tooth, index.! 
shell, propor- 
Length. Width. Proportions. Length. Width. Proportions. tions. 
mm. mm. p. ct. mm. mm. p. ct. Racks 
Inlaintreerire 404) 16.6554+.0244) 9.9316+.0128) 59.4950+.0649) 9.0113 .0141) 6.9732 .0107| 77.3341+.0786) 53.9653 =.0565| 2.3700+ .0422 
Banded, A..].... 18.05 9.30 $1.5 8.90 6.70 75.5 45.8 
1alligos 15.95 9.50 59.5 8.70 6.70 77.5 SES 3.0000 .3179 
(O8n acct 15.65 9.70 61.5 8.50 6.50 77.5 53.5 
ATER ee 407) 16.6546 .0245) 9.9285 .0128) 59.4803+.0659| 9.0091 = .0140) 6.9708 .0106) 77.3256+.0780) 53.9545+.0569| 2.3793+.0420 
STANDARD DEVIATION. 
Plains 404; 0.7291+=.0172) 0.3813=.0095) 1.9358+.0459) 0.4198+ .0096| 0.3181+.0075| 2.3431+.0556) 1.6854 .0399) 0.8849 .0298 
HNWeter eo cor 407 .7322+ .0173 -3818=+=.0091) 1.9719+.0466) .4193+.0099) .3181+.0075| 2.3336+.0552| 1.7031+.0402| .8872+.0297 
1The numbers are, respectively, 200, 3; 203. 
The statistics (table 139) are valuable mainly for an inter-valley comparison; 
yet it is significant that the banded shells are quite different from one another and 
hence are presumably sporadic products of plain parents rather than representatives 
of a distinct but feeble stock. They have no exact counterparts in the valleys on 
either side of Vahii. 
