~210 VARIATION, DISTRIBUTION, AND EVOLUTION OF THE GENUS PARTULA. 
Four Aionifaa snails were gravid, and contained 5 eggs and 4 plain, brown, 
and dextral young. No figures were procured in the case of the Aiurua series. The 
Vaiau records are almost complete (table 152). As regards the inheritance of the 
mode of coil, it is evident that the two classes are not genetically separate, for one 
of the reversed parents produced a single dextral offspring. 
TaBLeE 152.—Partula otaheitana affinis. Vaiau Valley. 
Fecunpity. HeERepIrty. 
NT T, J y 7 
SericauealiRecerds! No. of Per cent No. of NO. of} Total ENIEEASS Average Young, Young, Total. 
gravid.| gravid. | eggs. |young.|contents.|for gravid.| for all. dextral.| sinistral. 
| 
Dextral.. . 9 4 44.4 3 3 6 1.50 0.66 Adults: 
Sinistral. . 5 3 60.0 3 3 6 2.00 1.20 Dextral... 3 te 3 
Sinistral. . 1 2 3 
sRotalemmeee 4 2 6 
Hotrotunu To Haoma VALLEYs. 
Although the affinis collections from the remainder of Taiarapu are small, they 
are of much interest on account of their differing colonial aspects. In Hototunu, 6 
zonately banded shells occurred in a collection of 45 adults. In the next valley no 
such specimen was found in a short series of 6, but 1 plain sinistral individual was 
secured. Passing Aiavaro, where only sinistrorsa representatives of P. otaheitana 
were found, 1 out of 6 afinis from Vavii Valley is zonately banded. In Vaipoe the 
plain and the striped shells exist in the proportion of 4 to 3, respectively; while 
finally in Haoma the banded specimens dwindle again; some of the Vaipoe shells 
are so peculiar as to be worthy of illustration (plate 30, figs. 3 to 7). 
The statistics relating to the various colonies and to their subordinate classes 
(table 153) require no verbal amplification. So far as the figures are reliable, they 
indicate that each colony possesses dimensional characteristics of its own. 
Fecundity appears to be average (table 154) for the colonies which afford reliable 
data. The snails collected in Vaipoe were kept alive for several weeks, and hence 
there are no figures for that association. 
The data of heredity are unfortunately scanty, but they are valuable. In 
Hototunu 22 young of plain parents were all plain; out of 6 young produced by 
banded snails, 4 were plain and 2 only were banded. The Vaiaaia data are remark- 
able, as the table (154) shows; specifically a dextral plain adult bore a young one 
like itself, a dextral banded snail produced one of similar coil and pattern, while a 
sinistral plain animal contained a sinistral and banded embryonic snail—a type that 
did not appear in the small series of adults! The Vavii and Vaipoe colonies furnished 
no data. Inthe case of the Haoma series, all 28 young of plain parents were plain, 
and 2 young from banded adults were also plain. Here, then, we have a repetition 
of the situation observed in the colonies of the northern Taiapapu series. 
