80 
not due solely to the fact that smaller collections were secured here. 
VARIATION, DISTRIBUTION, AND EVOLUTION OF THE GENUS PARTULA. 
The Santa Rosa colony is made up principally of mitella and the sharply con- 
trasted phea-rubra class; its difference from the Tarague series must be real, and 
The statis- 
tics of record (table 30) show wide departures on the part of the solitary bicolor 
and phea-purpurea shells, but the figures are not outside of the ranges within 
which the other classes vary. ‘The statistics of lip-color and tooth-development 
(table 31) are self-sufficient. 
The notable features of the Asados collection are the absence of mitella, the 
abundant occurrence of mitella-rubra, and the substantial equivalence of the two 
color-orders of phza. 
extraordinarily consistent in their absolute measures, but they are highly variable 
in their proportions 
The statistics of table 30 show that the bicolor shells are 
The two phea orders are sensibly the same in shell propor- 
tions, although they differ greatly in absolute measures, while in the characters of 
Series. 
Lolo: 
Barrigarda: 
mitella...... 
mitella-rubra 
phea-rubra. . 
vespera-rosea,......... 
Ukudu: 
mitella...... 
mitella-rubra 
pheea-rubra. . 


No. 

TABLE 32.—Partula gibba, Guam. 
Length. 
mm. 
16.5671 +.0471 
16.3713 +.0579 
16.3427 +.0538 
16.4900 +.0635 
16.4527 +.0277 

17.0773 +.0548 
16.9500 +.0766 
16.8190 + .0833 
16.8028 +.0389 
16.8648 +.0295 
17.6368 +.0657 
17.2030 +.0999 
20.1500 
17.5684 +.0617 
17.4291 +.0660 
17.3926 +.0526 
17.3900 +.2847 
17.4000 +.1990 
17.3750 +.0839 

Shell. 
Width. 
mm. 
11.4371 +.0425 
11.4872 +.0424 
11.3291 +.0492 
11.3160 +.0564 
11.3937 +.0241 
11.9848 +.0631 
12.0000 +.0539 
11.5966 +.0508 
11.6722 +.0339 
11.7385 +.0258 
12.0962 +.0468 
11.8059 +.0582 
13.5000 
12.0465 +.0413 
12.1837 +.0589 
12.1894 +.0498 
12.5000 +.0 
12.2600 +.1665 
11.7500 +.0997 
69.1576—=.0932 

69.5330+.1021 
68.7535 +.2114 

MEAN VALUE. 
Proportions. 
dD. ct. 
69.0000 +.1582 
69.9468 +.1731 
69.1182 +.1839 
68.6800 +.2172 
70.1363 4.2345 
70.6667 +.2956 
68.9138 +.2314 
69.3889 +.1340 

68.7264 +.2624 
68.9117 +.3274 
67.5000 
69.9186+.2512 
70.3936 +.2001 
74.5000 +.0 
70.0000 +.5449 
67.7500 +.5528 

East Central Region. 
Length. 
mm. 
9.4314 +.0283 
9.3681 +.0333 
9.2564 +.0309 
9.3400 +.0366 
9.3540 +.0163 

9.8939 +.0329 
9.7833 +.0434 
9.8241 +.0471 
9.6130 +.0264 
9.7088 +.0195 
9.9566 +.0362 
9.7472 +.0442 
11.3000 
9.9253 +.0327 
9.9279 +.0378 
9.9170 +.0339 
10.0000 +.0477 
10.0333 +.0998 
9.7500 +.0559 
17.2000 +.1110 
17.9500 +.0550 
17.6000 +.5008 
18.0500 
11.7333 +.0865 
12.1000 +.0636 
68.3333 4.4027 
67.1666 +.4857 
12.3000 +.0954|69.5000 +1.4308 
12.1000 
67.5000 
9.9333 +.0494 
10.1000 +.0636 
10.0000 +.2384 
10.1000 
—!./| | SSSsSESSSSSSSSSSSSSSSeSeSeSeS 
17.5250 +.1219 
11.9500 +.0658/68.1667 +.3671 

10.0000 +.0515 



Aperture. 
Width. 
mm. 
6.8143 +.0220 
6.8532 +.0251 
6.7618 +.0261 
6.7880 +.0288 
6.8279 +.0131 
7.2151 .0327 
7.1667 +.0290 
7.3206 +.0344 
7.0445 +.0196 
7.1275 +.0153 
7.2585 +.0237 
71353:4:,0322 
8.3000 
7.2437 +.0222 
7.3465 +.0331 
7.3170 +.0322 
7.5000 +.0 
7.4333 +.0998 
7.2000 +.0754 
7.3353 +.0216 
7.2000 +.0527 
7.3000 + .0636 
7.4000 +.0477|74.5000 +1.4308|/56.5000 +.0 
7.7000 
7.3000 +.0420} 73.0000 +.3599/57.0000 +.1864 
72.8648 +.0804/56.7432 +.0613 

73.2912 +.0936|57.4066 +.0813 
73.0493 +.1693/56.2465 +.1122 
73.8921 +.1310)56.9216 +.0987 




























Length aper- 
ture + length 
shell, propor- 
Proportions. tions. 
p. ct. Pp. ct. 
73.0143 +.1440/56.8143 +.1101 
73.0957 +.1473/57.0319 +.1127 
72.9364 +.1652|56.5909 +.1205 
72.3600 +.1779|56.5400 +.1414 
72.8333 +.2156|57.8333 £.1376 
73.2500 +.3566|57.6667 +.2362 
74.0862 +.1960|58.1552 4.2113 
73.2223 +.1233]57.0463 +.1079 
72.9151 +.2079|56.1981 +.1280 
73.4412 +.2728|56.3824 +.2433 
73.5000 56.5000 
73.8256 +.1930/56.8721 +.1600 
73.8611 +.1982/56.8829 +.1354 
76.0000 +.2384/59.0000 +.2384 
74.3333 &.5372|57.3333 4.4329 
73.2500 +.6476!56.2500 +.2796 
72.5000 +.3179|55.3333 +.2103 
72.1666 +.1836|56.1666 +.3671 
75.5000 56.5000 
