PARTULA NODOSA. 99 
color-classes and of the two form-classes (table 46). All of the plain adults pro- 
duced only plain young, while the banded adults bore both kinds; certainly these 
classes can not be regarded as distinct. Mayer’s results on this point are confirmed. 
The two form classes, sinistral and dextral, bred true in my material; but in Mayer’s 
material a dextral individual bore one sinistral offspring and 4 out of 51 young 
produced by sinistral parents were dextral. 
Tas_e 45.—Partula nodosa leva. Maruapoo Valley. Pillar tooth. 
Tooth. 
G dlotal Mean value. Standard 
roup. num- Par 
Very Index. deviation. 
Large ber. 
0 Trace. | Tooth. large 
tooth. 
tooth 
Sinistralssplainys| 90 7a ereeeeinae 2 1 14 3 0 20 2.9000+ .1158 | 0.7681. 
Sinistral, banded, 1907........... 1 4 22 4 1 32 3.0000 .0856 | .7184 . 
Sinistral, plain, 1908............. 19 71 298 36 10 434 2.8779 .0228 1063. 
Sinistral, banded, 1908........... 9 34 97 23 7 170 2.9118 .0434 8391+. 
Mextralsplainy 1908s aaeceeeisaee 0 1 12 3 1 17 3.2353 .1054 6444. 
Dextral, banded, 1908........ ir 1 3 5 2 0) 11 2.7273 .1754 8624. 
| 
Siictall, all, WO% oc cocccccocccnc 3 5 36 7 1 52 2.9616= .0685 sUSYAZES . 
Sinigimall, alll, WOOB. ossccodobscced 28 105 395 59 17 604 2.8875 .0205 SKIES 
Dextral all OOSsamnaecice ire 1 4 17 5 1 28 3.0571+ .0990 SUUUNES 5 
Sinistralipal le ioccsueyvoyaeisis screens lave: 31 110 431 66 18 656 2.8933 .0196 (4545, 
TaBLeE 46.—Partula nodosa leva. Maruapoo Valley. 
FECUNDITY. 
: Percent} , Total |Average Average 
CHOU: RSSOREH Creanatel gravid. Eggs. | Young. contents.|for gravid.} for all. 
Sinistral, 1908..... 561 219 39.0 269 68 337 1S 0.6 
Dextral, 1908..... 27 11 40.7 14 1 15 1.4 0.5 
MAILE Ns ayt rene Se etias 588 230 39.1 283 69 352 1S 0.6 
Herepiry (1908). 
Young. 
USE ae Lice Total. 
Sinistral, plain. | Sinistral, banded. | Dextral, banded. 
Adults, sinistral, plain....... 50 0 O60 50 
Adults, sinistral, banded..... 6 12 cee 18 
Adults, dextral, banded ...... a RS 1 1 
56 12 | 1 69 
While it is theoretically possible that the directly coiled snails may be the 
descendants of recent emigrants from Punaruu, this does not seem probable. Obvi- 
ously these individuals are genetically related to the sinistral group, as proven by the 
Statistics of heredity and of form. Furthermore, the peculiar color-characters of 
the latter are shared with the former, in most cases. The absence of the white 
