g2 
The make-up of the 1909 series is as follows: 
Dextral. 
Sinis 
Per cent. 
Per cent. 
tral. 
No. 
14.3 7 
42.8 68 
20 
42.8 | 60 
All. 
Per cent. 
5 
a) 
a) 
off 
VARIATION, DISTRIBUTION, AND EVOLUTION OF THE GENUS PARTULA. 
All four divisions are represented in the dextral series of 1906, but unfortunately 
the colors of most of the shells were altered by contaminated formalin and the 
relative numbers in the several classes can not be determined with certainty. Only 
one sinistral specimen was obtained in the lower valley, and this was an immature 
member of Class II. 
TaBLe 38.—Partula nodosa composita. 
Taapuna Valley. 
Mean VALUE. 
Shell. Aperture. Length aper- 
ture + length 
CRON NO shell, propor- 
Length. - Width. Proportions. Length. Width. Proportions. tions. 
mm. mm. p. ct. mm. mm. Di Cle p. ct. 
Class I, 1909, dex. 6 | 16.0500 .1763) 9.7333 .1074| 60.3334 .2487| 8.6663 + .1539) 6.8000+ .0940} 78.8334 1.1012) 53.8333+.5430 
Class II, 1909,dex.| 64 | 16.0953 .0697| 9.6937+.0415| 60.2969+ .0580) 8.7312+.0358) 6.8562 .0308| 78.2500 .1885) 54.4219 .1462 
Class III, 1909, dex.} 20 ) 15.9050.0908, 9.7100+.0518} 60.9000+ .2356} 8.5500+ .0638) 6.8600 .0473; 80.1500 .3279) 53.7000+.2505 
Class IV, 1909, dex.| 57 | 15.7027.0811] 9.5281 = .0413} 60.5526+.2197) 8.4579 .0427| 6.7070 .0376| 79.3948 .2429) 53.5176+.1574 
All, 1909, dex..... 147 | 15.9153+.0470}] 9.6333 + .0259} 60.4796+.1240) 8.5979+ .0261} 6.7966 .0208) 78.9762 .1434! 53.9489+.0999 
All, 1906, dex..... 151 | 16.0692 = .0433| 9.6867 = .0179} 60.1623 .1073) 8.6443+ .0244) 6.8059+.0185| 78.6987 .1538) 53.6457+.0989 
All dexiiereec ise 298 | 15.9933 .0320} 9.6604 .0170} 60.3188 .0820| 8.6215+.0179| 6.8013+.0128| 78.8356 .1053] 53.7953+.0705 
NOW, Sto ooacocen 6 | 15.9000 = .2673} 9.9000 = .1350} 62.3333 .5372) 8.6333 .0936) 6.6667 = .0866| 76.8333 .9360| 54.3333 + .3693 
STANDARD DEyIATION. 
Class I, 1909, dex. 6 0.6403 = .1246|) 0.3902 .0759| 0.9031=.1758) 0.5588 .1088| 0.3416 .0664| 3.3993 .7786) 1.9720+.3839 
Class II, 1909, dex.| 64 .8267+ .0493| .4924+ .0293 -6876+ .0410) .4247+.0253) .3661+.0218) 2.2360 .1333) 1.7347+.1034 
Class III, 1909, dex.} 20 .6020+ .0642| .3434+.0366| 1.5620+.1666| .4232+.0451) .3137+.0334| 2.1743 .2318| 1.6613+.1771 
Class IV, 1909, dex.} 57 -9081+.0573} .4625+.0292) 2.4596+.1553} .4783+.0302) .3875+=.0245| 2.7189 .1717| 1.7621+.1113 
All, 1909, dex..... 147 .8460 + .0332| -4668+ .0183| 2.2299+.0877| .4697+.0185| .3742+.0147| 2.5775 .1014| 1.7966+.0706 
All, 1906, dex..... 151 .7889 + .0306) .3271+.0126) 1.9561+.0759| .4453+.0172| .3366+.0131| 2.8026 .1087| 1.8028+.0699 
ALdextnsy rere ks 298 .8211 += .0227) .4353+.0120} 2.1016+.0580) .4580+.0126| .3556+.0098) 2.6975 .0744) 1.8060+.0498 
<a |iP™ ise cps anel| = _———————————————— 
1909 Nsineeereree rie: 6 -9709+.1890) .4899=+=.0095) 1.9508+.3799| .3399+.0662) .3144+.0612 3.3993+ .0662| 2.7938+.2611 
the shells is given in table 38. 
The statistical description of the measurable and proportionate characters of 
In comparison with other colonies, the figures show 
a relatively large size; this and the complex make-up of the colony may be taken 
as the distinctive characters of the var. composita, so named for purposes of reference. 
The comparison of dextral and sinistral shells must be made on the basis of the 
1909 material alone, because adult reversed individuals were taken in that year 
only. Small as the sinistral group is, the differences between the contrasted groups 
