PARTULA NODOSA. stole) 
Coming now to the characters of the aperture, we find some correspondence 
with the above comparative results. For example, in passing from Taapuna to 
Punaruu, the length is reduced, but the width increases, bringing about a great 
increase in the degree of stoutness. Going to Maruapoo, a distinct drop in propor- 
tion is noted, as in the whole shell, due to a decrease in width that is relatively 
greater than the reduction in aperture length. The Atehi shells do not exhibit the 
same agreement; true, they are shorter and narrower in the aperture dimensions as 
compared with the shells of neighboring valleys, but the reduction in the second 
TaBs_e 53.—Partula nodosa. Comparison of valley colonies. 
Mean VALUE. 
Shell. Aperture. Length aper- 
Series No ture + length 
. i L ; : : shell, propor- 
ength. Width. Proportions. Length. Width. Proportions. Rion 
mm, mm. p. ct. mm. mm. p. ct. p. ct. 
Taapuna, dex. .| 298 | 15.9933 .0320| 9.6604 .0170) 60.3188 .0820) 8.6215+=.0179) 6.8013 .0128) 78.8356 .1053) 53.7953 .0705 
Taapuna, sin... 6 | 15.9000 + .2673| 9.9000+.1350) 62.3333 .5372) 8.6333 + .0936) 6.6667 = .0866| 76.8333 .9360| 54.3333 + .3693 
Punaruu, dex. .| 160 | 15.5769+.0468| 9.5637 +.0245| 61.3625+.0986) 8.4212+.0248) 6.8650+.0207) 81.4875+ .1382) 53.9250+.0899 
Maruapoo, dex.| 28 | 15.6072 .1113) 9.2215+.0583) 58.9286 .2879) 8.2000 .0599) 6.3786 .0459| 77.8572 .3560) 52.4286+.2070 
Maruapoo, sin .| 649 | 15.5497 .0196| 9.3409+.0107) 60.0439+ .0642) 8.1539 .0107) 6.3922 .0100| 79.3968 .0812) 52.2412+.0484 
Atehi, dex..... 4 | 14.0750 .2225) 8.8500 .0559| 62.7500 .6021| 7.7500 .0876) 5.8500 .0559) 76.0000 1.1316) 54.5000 .5841 
Papehue, dex...) 205 | 14.7647 .0311) 9.2044 .0187) 62.3292+.0911| 8.0717+.0173| 6.4210+.0142) 79.5780 .1150) 54.5192+.0707 
Aoua, dex..... 382 | 14.4249 .0231] 8.9492 .0141| 61.9424 .0750| 7.9058 .0131) 6.3519 .0108| 80.2146 .0872| 54.6544 .0545 
Orofere, dex...| 18 | 15.3667=.1899| 9.2889 .1014| 60.3889=.2798| 8.2778+.0988) 6.6111+.1018) 79.8333 .3594| 53.7778 .2531 
All, dex....... 1,095} 15.1281 .0206| 9.2925=+.0106) 61.3886+.0452) 8.2200+.0103) 6.5652 .0083| 79.8388 .0758) 54.2169 .0349 
STANDARD DEVIATION. 
Taapuna, dex..| 298 | 0.8211+.0227/ 0.4353+.0120) 2.1016+.0580) 0.4580 .0126) 0.3556 .0098} 2.6975+ .0744) 1.8060+.0498 
Taapuna, sin... 6 -9709 = .1890| .4899+.0095) 1.9508+.3799| .3399+.0662) .3144+.0612| 3.3993 .0662| 2.7938+.2611 
Punaruu, dex. .| 160 .8783+ .0331| .4596+.0173) 1.8488+=.0697| .4654+.0175|} .3883+.0146| 2.5908 .0977| 1.6865+=.0636 
Maruapoo, dex.| 28 .8736+.0787| .4578=.0412) 2.2588+.2035| .4705+.0424| .3599+.0324| 2.7930 .2517) 1.6241+.1464 
Maruapoo, sin..| 649 .7407 = .0139| .4061+.0076) 2.4239+.0454| .4027+.0076) .3783+.0071| 3.0678 .0565| 1.8246+.0342 
Atehi, dex..... 4 .4918=.1573} .1658+=.0395| 1.7853+.4258} .2598+.0619) .1658+.0395| 3.3556 .8002| 1.7320+.4130 
Papehue, dex.. .| 205 .6598+ .0220| .3978+.0132| 1.9343+.0644| .3693+.0122| .3024+.0100) 2.4422+ .0813) 1.5004+.0500 
Aoua, dex..... 382 .6707 + .0163| .4079+=.0100} 2.1708+.0530) .3795+.0093) .3126+.0076) 2.5242 .0617| 1.5769+.0385 
Orofere, dex....) 18 | 1.1945+.1343) .6376+.0717| 1.7603+.1978) .6214+.0699| .6402+.0720) 2.2608 .2541| 1.5918+.1790 
JNIL CEe86 so ene 1,095 | 1.0097+.0146) .5201+.0075) 2.2158+.0320} .5059+.0073) .4086+.0059) 2.7374 .0536| 1.7149 .0247 
TaBLe 54.—Partula nodosa. Progressive comparison, by valleys, of dextral groups. Differences in mean value. 
Aperture. Length aper- 
ture + length 
shell, propor- 
tions. 
Valley. 
Length. Width. Proportions. Length. Width. Proportions. 
Taapuna... mm 
0 mm. Dp. ct. 
—0.4164+ .0567 
—0.0967 = .0298) +1.0437+.1286 
mm mm 
; D. ct. 
—0.2003 + .0305| +0.0637 + .0243 
+2.6519+ .1737 
p. ct. 
[+ .1297=.1142] 
Punaruu... 
[+ .0303+.1215] -3422 + .0632) —2.4339= .3043 .2212+ .0648|— .4864+.0503) —3.6303+ .3819| —1.4964+.2257 
—1.5019=+ .2487 -3715+ .0807) +3.8214+.6674 4500+ .1062)— .5286+.0723|[ —1.8572+1.1862]) +2.0714+.6197 
+ .6897 + .2246 3544+ .0589|[— .4208+.6089]/4 .3217+.0893)/+ .5710+.0576) +3.5780+1.1374 |[+ .0192+.5883] 
— .3398= .0387 .2552 + .0234| — .3868+ .0996 .1659+ .0217)— .0691+.0178 
+ .6366 .1443 
[+ .1352+.0892] 
+ .9418+.1913 3397 = 1023) —1.5535+.2897 |4- .3728+.0996)+ .2592+.1023)[— .3813+ .3698]) — .8766+.2589 
