PARTULA NODOSA. 95 
The statistical characters of the Punaruu shells are given in table 41, and from 
these it appears that the three annual series differ in their measurements just as 
they do in the representation of the several color-types. The colony is by no means 
as homogeneous as might be expected from its circumscribed area of habitation. 
The comparison of the colony as a whole with that of Taapuna may be deferred to 
the concluding summary. 
TaBLe 41. Partula nodosa composita. Punaruu Valley. 
MEAN VALUE. 
Shell. Aperture. Length aper- 
ture + length 
Group. | No. shell, propor- 
Length. Width. Proportions. Length. Width. Proportions. tions. 
mm. mm. D. ct. mm. mm. p. ct. Dp. ct. 
1906..... 68 | 15.4823 .0353| 9.5617 =+.0325) 61.6323+.1605) 8.4264+ .0356) 6.8676+.0295 81.5882 .1723) 54.2794+.1261 
IONS, oo0¢ 34 | 15.7823+.1173| 9.6176+.0607| 60.9706+.2122) 8.5059 .0670) 6.9353 .0509| 81.3823 .2979| 53.7353 .2156 
1909..... 58 ) 15.5672+ .0687) 9.5348+ .0395) 61.3758 .1471| 8.3689 .0365| 6.8207 +.0337) 81.4310 .2716| 53.6207 .1517 
Class I.| 51 | 15.6029+.0786) 9.6411 .0361| 61.7745+.1885)] 8.4804 .0396 6.9117 + .0320| 81.3039 = .2578) 54.2058 .1488 
Class II.| 102 | 15.6382 .0603| 9.5451 .0329} 61.1863=.1179| 8.4117+.0439| 6.8627 = .0273) 81.5784 .1706| 53.8333+.1146 
Class III. 6 | 15.2000 .2224) 9.3000 .0899| 61.3333+.2938) 8.1666 .0936| 6.6000 = .0693) 81.3333 .6441| 53.5000 .4900 
Class IV. 1 | 15.5000 .| 9.1000 .| 58.5000 .| 8.0800 .| 6.3000 ..| 78.5000 .| 51.5000 
aor 160 | 15.5769= .0468) 9.5637 +.0245 CUE oe 6.8650 .0207| 81.4875 + .1382) 53.9250 .0899 
STANDARD DegvVIATION. 
MONG. coos 68 | 0.4323+.0249) 0.3975+.0230) 1.9622+.1135) 0.4351.0252) 0.3608+.0208) 2.1065+=.1218) 1.5420+.0891 
1OO0SHere 34 1.0139 .0829) .5251+.0429) 1.8349=.1500) .5790+.0474) .4405+.0360) 2.5755=.2106|) 1.8639 .1524 
1909..... 58 .7755+.0486| .4457.0279| 1.6613+.1040 4120 0258) 3804 + 0238) 3.0674 .1920) 1.7128 .1073 
Oass ial) Sil .8325=.0556) .3825+.0255| 1.9959=.1333 .4196 + .0280) 3394 .0226| 2.7298+=.1823} 1.5755+.1052 
Class II.} 102 .9033=.0426) .4933=.0232) 1.7656+.0834| .6577+=.0310| .4085+.0193) 2.5541+.1206) 1.7169+.0810 
Class III. 6 .8077=.1572| .3265+.0636| 1.0671+.2077} .3399+.0662| .2516+.0490) 2.3391+.4554| 1.7795+.3465 
Class IV. Ne ea cree Merrcrerscall| cartsils vavogeus |e » ebersyees hee Bat eter ters in| [ha ars eae eset sav coars Scat 
iN otercrore 160 -8783 + .0331| .4596+.0173) 1.8488=.0697| .4654.0175) .3883+.0146) 2.5908+.0977) 1.6865+.0636 
The four color-classes differ somewhat, although only Classes I and II comprise 
enough individuals to warrant a statistical comparison. 
In two of the three pro- 
portionate determinations, the differences in question appear to be significantly large 
in relation to their probable errors. 
The tooth is almost invariably developed to some degree (table 42). 
two shells are devoid of any trace of this structure. 
The statistics of fecundity (table 42) show a low rate of reproductive activity 
Only 
in the case of the 1906 series, taken in the wet and hot season; the low rate is indi- 
cated both in the percentage of gravid individuals and in the number of young and 
eggs borne by the reproducing snails. In 1908 remarkably high percentages were 
obtained, but in the corresponding period of 1909 the figures are low again. It 
would seem that the resumption of breeding is not entirely determined by the advent 
of heavier rains and hotter weather. 
The data of heredity (table 42) prove only that banded young are sometimes 
produced by plain parents, and that plain young appear among the offspring of 
contrasted adults. As in Taapuna the color-classes are not absolutely fixed and 
