PARTULA CLARA. 63 
evenly colored than in the more northern valleys (figs. 19 and 21, plate 20, the 
former somewhat decorticated). The specimen shown in figure 22, plate 20, is an 
unusually large example from Papehue; it well illustrates the oral aspect of the 
specimens from this territory. 
That the lighter and darker shells are not genetically distinct, like some of the 
color varieties found elsewhere, is indicated by the fact that some of the former 
bear dark-colored young, while dark adults sometimes bear lighter young. Satis- 
factory quantitative determinations have not been possible in the case of the series 
from this group of valleys, because many individuals were transported alive to 
America, wherefore the exact parentage of the young snails brought forth during the 
journey could not be determined. 
TaBeE 21.—Partula clara parva. Statistical description of shell characters. 
MEAN VALUE. 
Shell. Aperture. Length aper- 
ture + length 
Valley. No. SAM, we 
Length. Width. Proportions. Length. Width. Proportions. portions. 
mm. mm. p. ct. mm. mm. | p. ct. Ducts 
Punaruu... 6 | 14.7500+.1908) 8.5000+.1146) 57.8333 .5659) 8.1333 .1288) 6.1666+.0821) 75.6666+.2939) 54.8333 .3045 
Maruapoo.. 3 | 13.2500+.0954) 7.5000+.0636| 56.1667 =.4856| 7.3666 .0367| 5.5666+.0367| 74.8333+.4856| 55.1666+.1836 
Atehitverienr 20 | 15.0350 .0647| 8.2500+.0414| 54.6500+.2199| 8.2300+.0408) 6.1600+.0318 74.8000+.2616) 54.5500+.2919 
Papehue....| 30 | 14.9300+.0799) 8.4133 .0461) 56.1000 .1477| 8.4133+.0567| 6.2734+.0453 74.6333 + .2394| 56.0000 .1704 
JN Gamo oeon 59 | 14.8720 .0602| 8.3203.0350) 55.6186 .1525 8.2695-& .0402| 6.1881+.0300) 74.8051 .1544) 55.3474 .1479 
STANDARD DEVIATION. 
Punaruu... 6 | 0.6928+.1349) 0.4163+=.0811) 2.0548=.4001| 0.4678+.0911) 0.2981 =.0580, 1.0671+.2078) 1.1055+.2152 
Maruapoo. . 3 2449 0674) .1633+.0449| 1.2471 .3433| .0943+.0260) .0943=+.0260) 1.2471+.3433 4714+ .1298 
Atehion as 6) 20 4292+ .0458| .2747+.0293) 1.4585=.1555) .2703+.0288) .2107+.0225) 1.7349+.1849) 1.9358 .2064 
Papehue....| 30 -6490+ .0565| .3748=.0326) 1.2000+.1044| .4609+.0401| .3678=+.0320) 1.9447=.1692) 1.3844+.1204 
ALR se eiirec|) 59 -6878+.0427| .3994==.0248| 1.7377+.1079| .4581=.0284| .3420+.0212| 1.7587+.1092| 1.6855+.1046 
Partula clara incrassa var. nov.—Aoua Valley. 
Passing to Aoua, the next valley to the south, a variety is found that is extra- 
ordinarily distinct from var. parva described above, as well as from the shells that 
are met with in the succeeding series of valleys. The individuality of this colonial 
variety is expressed in (a) peculiar color-types, (b) consistent differences in the form 
of the shell, (c) the thinness of the lip, (d) the occurrence of unique banded mutants, 
and (¢) the occurrence of specimens with a trace of a pillar tooth. The thinner 
texture of the shell, and especially of the last whorl and lip, may be taken as the 
diagnostic character of this division; hence the varietal designation, incrassa. The 
shells are illustrated as figures 23 to 36 of plate 20. 
In all, 67 adults were secured, and these constitute 5.92 per cent of the popula- 
tion; 55 are plain and light; most of these exhibit the uniform corneous coloration of 
the species in general (figs. 23 to 27, plate 20), but distinct cross-streaks are superadded 
in others (figs. 29 and 30, plate 20). A rose-colored spire is sometimes found (fig. 24, 
plate 20), which is something that occurs nowhere else in this species. Purplish- 
