182 
VARIATION, DISTRIBUTION, AND EVOLUTION OF THE GENUS PARTULA. 
order, collectively demonstrate how the several colonies display independent com- 
binations of structural qualities. 
To cite certain significant comparisons, in the 
first step (Tuauru to Ahonu), the shells become longer and wider, and possibly 
stouter, while at the next (Ahonu to Papenoo) they decrease in length but increase 
in stoutness; from Faarumai to Tiarei there is again a decrease in length with an 
increase in proportions, but from Tiarei to Mahaena the absolute measures diminish 
with a certain increase in stoutness; again the shells of Tautira as compared with 
TaBLe 115.—Partula otaheitana rubescens. 
Mean VALUE. 
Statistical summary. 
Shell. Aperture. Length aper- 
| ture + length é 
‘ 
Valley. No. ] analll, meaner Tooth, index. 
Length. Width. Proportions. Length. Width. Proportions. tions. 
mm. mm. p. ct. mm, mm. p. ct. p. ct. 
Tuauru.. .| 8} 19.5000 .1333, 10.5500 .0884) 54.0000+.4130) 9.7000+.0754) 7.2250+ .0473) 75.1250+ .4608) 49.3750+.4034| 1.1250 .0789 
Ahonu....| 145) 20.6603 .0533) 11.3166 .0296) 54.6379 .1295) 10.2766 .0286) 7.7662 .0236) 75.4379 .1540} 49.6586 .1016) 2.2809 .0675 
Papenoo..| 336 20.3765 .0340| 11.3024 .0207) 55.3690 .0865) 10.3280+.0195| 7.6994 .0168) 74.5268 .1104) 50.6637+.0714) 2.4828+ .0371 
Faarumai., 19} 20.5395+.1382! 11.8578 .0907) 57.6579 .5225| 10.7632+.0689| 8.2053+.0628) 76.4474 .3839) 52.2368+.3129) 1.0000+0 
Tiarei....} 15) 19.9833 .1266) 11.6467 += .0746) 58.3000+.5135| 10.2733 .0538) 7.9000= .0492) 76.9000 .5313 51.3000 + .2310) 1.0667 + .0434 
Mahaena. 6| 18.5833 .1298) 11.1667+.0757| 60.0000+.5450) 9.8667 .0668) 7.5667 +.0519| 76.1667 .5877) 53.0000 .1377| 3.6667 +.2052 
Paraura..| 89} 19.1545+.0734) 10.8438 .0369| 56.6798 .1570| 9.7899 .0383) 7.6708 .0280} 78.4101 .1750) 51.0618+.1325) 1.9776 .0660 
Papeiha. .| 111) 20.1320+.0633) 11.2856+.0327| 56.1829 .1501) 10.1901 .0325) 7.8207 .0262) 76.8153+ .1744) 50.5901+.1072) 1.0089=+ .0060 
Utuufai.. 5} 19.9500 .1206 11.2200 .1182) 55.7000 .8433) 10.2600+ .0886) 7.5000+ .0934| 73.7000+ 1.2568) 51.1000 .2413) 1 
Haavini. .| 214) 19.6776+.0426) 10.9355+.0228) 55.6449+.1188) 9.9813=.0230) 7.6486+.0169| 76.6542 .1118) 50.7666 .0863) 1 
Tautira..| 82) 20.2622 .0530) 11.8854 .0357| 58.7561+.1577} 10.5098 .0310) 8.2536 .0293} 78.4878 .1903} 51.8780 .1320) 1 
Aiurua...) 119] 20.3130 .0616) 11.7000 .0294) 57.7017 .1568) 10.2933 .0278) 7.9403 + .0225| 77.2479 .1476| 50.7101 .1096) 1 
Oopu... | 272| 22.8306+.0462) 12.8949 + .0222) 56.5074 .1044) 11.5265=£.0225| 8.6662+.0175| 75.2022 .1193 50.5037 +.0731| 1 
StanpDARD DeyIaTION. 
Tuauru... 8} 0.5590 .0942) 0.3708+.0625) 1.7320+.2920) 0.3162+.0533) 0.1984+ .0334) 1.93244 .3258) 1.6918+.2852) 0.3308+.0558 
Ahonu....} 145 -9517 + .0377 .5291+.0209) 2.3126+.0916 -5106+.0202) .4215+.0167| 2.7498+= .1089) 1.8144+.0718) 1.2092 .0477 
Papenoo..| 336 -9246+ .0240 .5627+.0146) 2.3504+.0612 5314 .0138} .4555+.0119) 3.00134 .0781) 1.9395+.0505) 1.0172 .0262 
Faarumai.| 19} -8931+.0977 .5861+.0641) 3.3758+.3695 4450+ .0487) .4059+.0444) 2.4809 .2715| 2.0220+.2213) 0 
Wiareinrer| mel .7272 += .0895 4287+ .0527| 2.9484+.3631 .3087 = .0380} .2828=.0348) 3.0506+ .3754) 1.3266+.1633) .2494+.0307 
Mahaena. 6) .4713+.0918) .2749+.0535| 1.9791+=.3854) .2427+.0472) .1885+.0367) 2.13444 .4156 .5000+.0974) .7454+.1451 
Paraura..| 89] 1.0273.0519) .5158+.0261) 2.1958+.1110) .5363+.0271) .3915+.0198) 2.4478 .1237| 1.8539+.0937| .9238=.0467 
Papeiha. .| 111 -9884= .0448 .5106+.0231) 2.3439+.1061 -5075=.0230) .4100+.0185} 2.7245 .1233) 1.6741+.0758} .0940+=.0042 
Utuufai.. 5 .4000+=.0853| .3919+.0836) 2.7856+.5963} .2939+.0626) .3098+.0660) 4.1665+ .8887 -8000 + .1706} 0 
Haavini. .| 214 9250+ .0301 -4939=.0161) 2.5764 .0840 .4981+ .0163) .3660+.0119| 2.4244 .0790) 1.8718=+.0610) 0 
Tautira..| 82 -7113+.0375 4796+ .0252) 2.1175+.1115) .4166+.0219) .3930+.0207| 2.25544 .1346) 1.5273+.0933] 0 
Aiurua...| 119 -9969 = .0435 4738+ .0208) 2.5356+.1109 -4490+.0196) .3644=.0159) 2.3877 .1044) 1.7722+.0775| 0 
Oopu....| 272) 1.1298+.0327) .5420+,0157) 2.5523+.0738| .5497+.0159| .4284+.0124| 2.9172+ .0844) 1.7874+.0517| 0 
those of Haavini are far longer, wider, and stouter. 
In brief, then, a greater average 
length of the shells in one colony as compared with those of a neighboring valley is 
not always accompanied by more marked slenderness in proportions, or vice versa. 
A similar lack of consistency might be pointed out for the characters of the aperture, 
and for the relation of the aperture to the whole shell in length. Finally, the data 
relating to the columellar tooth provide an additional group of facts supporting the 
view that differences in hereditary constitution and not differences in environment 
are accountable for the colonial variations displayed by rubescens. 
