230 VARIATION, DISTRIBUTION, AND EVOLUTION OF THE GENUS PARTULA. 
represented than in Apirimaue. ‘The dextral adults belong to cestata (plate 30, fig. 
45) and phea (plate 30, figs. 47 to 49), but in addition one immature specimen of the 
apex type was found (plate 30, fig. 39). 
The statistical data (table 173) bring out very marked differences between the 
sinistral and dextral divisions, and between color-classes of the same mode of coil. 
As regards the first point, it appears that in all of the eight characters the differences 
are beyond the scope of probable error. In the second connection, it is interesting 
to find that sinistral apex are larger and somewhat narrower than cestata of the same 
coil, for in other valleys they have not differed in both of those ways. 
reversed coil is much like cestata. 
in the way of a columella tooth. 
TaBLeE 173.—Partula otaheitana sintstrorsa. 
Mean VALUE. 
Titaviri Valley. 
Phea of the 
All of the sinistral groups exhibit little or nothing 
Shell. Aperture. Length aper- 
Series. | No SEG SE Tooth, index. 
shell, propor- 
Length. Width. Proportions. Length. Width. Proportions. tions. 
mm. mm. p. ct. mm. mm. p. ct. p. ct. 
apex, sin..... 25 | 20.1260+.1219| 11.0760+ .0583) 54.9000 + .2804) 10.2040+ .0656| 7.6440+ .0542| 74.8200 .3694| 50.7000 .2473) 1.0000+.0 
cestata, sin...) 115 | 19.6908+.0428} 10.8530 .0329) 55.0452 .1694) 10.1156 .0302| 7.5678 .0254| 74.8739 + .1976) 51.3434 .1166) 1.0435 += .0183 
phea, sin....| 25 | 19.6460.1504| 10.9880+.0571) 55.9000+ .4333] 10.1000+.0586| 7.5160+.0586| 74.3000+.4364| 51.4600+.2684| 1.3462+.0894 
| LN | 
ANIL, SiN 6 0000 | 165 | 19.7500+ .0483) 10.9073 +.0264| 55.1697 +.1426) 10.1267+.0249| 7.5715+.0215] 74.7788 + .1629| 51.2636+.0991| 1.0774+.0188 
cestata, dex . .| 15 | 18.4300+.1433) 10.5266+.0659| 57.0333 .3701) 9.7133+.0601) 7.1933+.0461) 73.7000 .3377| 52.8333 .3027| 2.2000+.2479 
phea, dex... .| 62 | 18.0403+ .0669| 10.3705 + .0303) 57.3871 .1801) 9.5645 .0421) 7.0226+ .0281) 73.2903 + .2182) 52.7903 .1763) 3.1935 + .1108 
| | a 
INVG G25 5060 | 77 | 18.1162+.0618) 10.4013+.0280) 57.3182 .1334|) 9.5935+.0514| 7.0558+.0248) 73.3701+.1880| 52.7987 +.1537) 3.0000+.1058 
STANDARD DEVIATION. 
apex, sin..... 25 0.9035 .0862} 0.4320+.0412) 2.0784+.1983) 0.4870+.0464) 0.4021+.0383] 2.7381+.2612| 1.8330+.1749] 0 
cestata, sin...] 115 -6815 + .0303) = .5231+.0233) 2.6934+.1198) .4808+.0213) .4042+.0179) 3.1414+.1397) 1.8537+.0824| .2918+.0129 
phea, sin....} 25 1.1151+.1063 -4236+ .0404| 3.2124+.3064 4345+ .0414| .4342+.0414) 3.2249+.3086) 1.9895+.1898) .6762+.0632 
INL SiMe oooac 165 -9191+ .0341 .5034+.0187| 2.7158+.1008 4750+ .0176| .4101.0152} 3.1034+.1152) 1.8872+.0701) .3619+.0133 
cestata, dex..| 15 .8231+.1013 .3785 + .0466| 2.1250.2617 -3452 + .0425) .2619+.0326} 1.9391+.2388) 1.7384+.2140) 1.4236+.1753 
phea, dex...| 62 -7807 + .0473) = .3540+.0214; 2.1031+.1273)| .4922+.0298) .3279+.0199|} 2.5472+.1543} 2.0587+.1246) 1.2931+.0783 
INU, CEs o00¢ 77 -8041+ .0437)  .3641+.0198) 1.7358+.0943) .4688+.0363| .3233+.0175| 2.4460+.1329] 2.0004+.1087) 1.3769=.0748 
1The numbers in the sinistral groups are 
27, 115, 26; 168. 
Among the dextral shells, where apex does not appear, cestata and phza are alike 
in being far shorter and relatively stouter than their sinistral counterparts, while 
the tooth attains a remarkable degree of development. 
The second class resembles 
affinis so greatly that its parallel origin seems almost impossible; yet the data on 
heredity are such as to prove the sinistrosa nature of all of the dextral individuals 
in this valley. 
The number of embryonic young is small (table 174) on account of the relatively 
large number of eggs as compared with unborn snails of fuller growth; the material 
was secured in the wet season of 1906, when reproductive activity had only recently 
been resumed. Classification of such young as were found could not be made 
parallel to that of the adults, because the colors of the embryonic shells were very 
