PARTULA NODOSA. 93 
are well marked in everything save total length and aperture length. The propor- 
tionate figures show decidedly significant peculiarities of the reversed group. 
A second analytical result follows from the data given, viz, that the series of 
1906 (from the lower level) differs from the 1909 collection (which was taken in the 
higher parts of the valley). Without enumerating the details, it may be said that 
the former shells are more elongated and more slender in proportions. 
Finally, we may compare the four color-classes of the dextral 1909 series, 
omitting the 1906 collection for the reasons stated. It appears that Classes I and 
II are much alike in statistical characters, while Classes III and IV form a couple. 
At first sight it would seem that the two classes of unbanded shells ought to resemble 
each other, and that the two classes of banded individuals should be similar in other 
respects. ‘The facts are otherwise, whatever their significance may be. The pillar 
tooth is variously developed (table 39), being absent in only a small percentage of the 
shells. In more than 83 per cent it is prominent, attaining a large size in a few cases. 
TasLeE 39.—Partula nodosa composita. Taapuna Valley. 
Tooru. 
None. Trace. Tooth. Large tooth. 
Series. Total. 
No. |Per cent.| No. |Per cent.| No. |Per cent.} No. |Per cent. 
1909, dextral... 6 aor 21 Bese 118 sooo 3 os 148 
1909, sinistral... 0 x eles 2 Sate 5 Severe 0 eestohe 7 
1906, dextral... 5 Send 12 aeeahs 139 2 158 
MOtali a aieiercreiesss 11 85 35 lita 262 83.7 5 1.6 313 
FEcunpITY. 
iS A Per cent Total | Average | Average 
Series. Records.) Gravid. gravid. Eggs) pv oung. contents.|for gravid.| for all. 
1909, dextral...... 125 49 39.2 67 13 80 1.6 0.6 
1909, sinistral..... 6 2 S3h3 0 3 3 68) 158) 
1909%ralley cick 131 51 38.9 67 16 83 1.6 0.6 
LOOG EA aie Srna 122 43 35.2 27 44 71 1.6 0.6 
HereEDITY: CoLor-PATTERN. Herepity: Cott. 
Young, | Young, Total 
Young, | Young, 
unbanded. | banded Total. 
dextral. | sinistral. 
Adults, unbanded.. 6 1 7 
banded.... 
Adults, dextral..... 57 0 57 
sinistral. ... 
The statistics relating to fecundity show a low productivity in both years 
(table 39). The percentage of gravid individuals is slightly higher for the drier 
season of 1909, but in both years the figures are low as compared with those for 
many colonies of P. clara. Still more striking are the low percentages of young and 
eggs, as given in the last two columns; these are substantially the same for the wet 
season of 1906 and the drier season of 1909. 
