166 VARIATION, DISTRIBUTION, AND EVOLUTION OF THE GENUS PARTULA. 
examples of the whole rubescens series; indeed, in depth of color some of them rival 
the brown affinis which inhabits this and neighboring valleys. In statistical char- 
acters (table 109) the two subordinate divisions of the yellow class are substantially 
alike; only in the proportions of the aperture is there an essential dissimilarity. 
The red-brown shells as a class are distinctly different; they are smaller in all four 
of the absolute measures, and they are narrow in the proportionate figures relating 
to the shell as a whole and to the aperture, while finally their apertures are longer in 
proportion to the length of the whole shell. In some but not in all of these relations 
to the yellow class they resemble the Tautira and Tahiti nui shells, and differ from 
the red class of Haavini. 
TasLe 109.—Partula otaheitana rubescens, Aiurua Valley. 
MEAN VALUE. 
Shell. Aperture. Length aper- 
Series. No. ture =wlength 
shell, propor- 
Length. Width. Proportions. Length. Width. Proportions. tions. 
mm. mm. p. ct. mm. mm. p. ct. p. ct. 
Yellow, A....| 81 | 20.3858.0731) 11.7642+.0356| 57.8457 .1953) 10.3074 .0395| 7.9913 .0280) 77.6852 .1794| 50.6605=+.1365 
Yellow, B....| 20 | 20.4000+.1042) 11.7400+ .0492|) 57.5500+.2880) 10.4000 .0552| 7.8800 .0466) 75.7500 .2935) 50.8000 .1913 
Yellow, all....} 101 | 20.3886= .0622) 11.7594 .0302) 57.7871+.1669| 10.3257 + .0296| 7.9693 .0245| 77.3019 .1632} 50.6881 .0508 
teioanooudon 18 | 19.8889 .1979| 11.3667 .0734| 57.2222 .4364| 10.1112+.0715| 7.7778 .0499| 76.9444 .3276| 50.8333+.3179 
All. 119 | 20.3130 .0616} 11.7000+.0294) 57.7017+.1568| 10.2933 .0278| 7.9403+.0225| 77.2479+.1476| 50.7101+.1096 
STANDARD DEVIATION. 
Yellow, A....| 81 | 0.9750.0517) 0.4759+.0248) 2.6065=+.1379| 0.5281+.0279| 0.3746+.0198) 2.3939+.1267| 1.8220+.0965 
Yellow, B....} 20 -6910 = .0737 -3262+ .0348] 1.9096+.2036 3660+ .0390} .3088+.0329) 1.9461+.2075) 1.2688+=.1353 
Yellow, all....| 101 -9257+.0440) .4507+.0213) 2.4869=+.1180) .4411+.0209| .3652+.0173) 2.4311+.1154| 1.7275+.0359 
IZelsooosocdd| 13 1.2450+.1399} .4619+.0519|} 2.7448+.3086| .4496+.0505| .3137+.0353) 2.0608+.2316| 2.0000 .2248 
IAM) aisteeveree- sorrel ALLO 9969 + .0435 4738+ .0208] 2.5356+.1109| .4490+.0196) .3644+.0159| 2.3877+.1044| 1.7722+.0775 
Only 9 individuals provided records of fecundity and heredity. All of these 
were gravid and contained 17 eggs, together with 13 advanced young. They 
belonged to the yellow class and bore 7 young with and without the red tip, as well 
as 6 red offspring. The paucity of data, however, renders these relations of little 
value in this case. 
OOPU VALLEY. 
Up to this point, the description of the several colonies of rubescens has followed 
the regular geographical sequence from the most northerly valley of Tuauru down 
the eastern coast of Tahiti nui and around the north and east sides of Taiarapu to 
Aiurua, with which valley this form stops. Now it is necessary to return to Tahiti 
nui, so as to consider the large and flourishing colony in Oopu Valley, which lies just 
south of the main mountain ridge terminating at the extreme southeastern point 
of the major island-mass. Obviously the region about Oopu articulates more 
directly with the eastern sector than with those parts of Taiarapu in which rubescens 
occurs, but as the Oopu colony is the only one on the south side—excepting a single 
