phea striata 
270 
Series. 
confluens. . . 
cestatameriirrarer 
phea striata 
cestata 
confuens. . . 
VARIATION, DISTRIBUTION, AND EVOLUTION OF THE GENUS PARTULA. 
Statistically (table 224) the two groups of unbanded shells prove to be virtually 
identical; the cestata group departs from the others in certain intrinsic characters of 
the aperture and in its relative length as compared with that of the whole shell. 
Taken collectively, the shells of this colony fall far below those of the sinzstralis 
association of Vaipuarii (vide ante) in absolute dimensions, while they are more 
tightly coiled as indicated by the greater proportionate measures. 
TaBLeE 224.—Partula otaheitana crass. 
Mean VALUE. 
Length. 
mm. 
17.1997 = .0346 
17.1053 .0505 
17.1250+.0961 
17.1661+ .0274 
0.7235+ .0244 
-7256+ .0357 
-6978 = .0679) 
Shell. 
Width. 
Proportions. 
Length. 
Aperture. 
Width. 
mm. 
9.6819+ .0171 
9.6575 + .0255 
9.7334 .0403 
p. ct. 
56.2035 + .0935 
56.4574 .1679 
56.6667 + .2772 
mm. 
9.0920+ .0192 
9.0447 + .0279 
8.9834 .0483 
| 9.6785 .0135 
| 0.3576 .0121 
3671+ .0180 
.2925 * 0285 
The matter of the pillar tooth (table 225) demands a special word. 
-7235+ .0194 
| 3577+ .0096 
56.3139 = .0800) 
9.0697 + .0151 
mm. 
6.7905 + .0153 
6.7213 + .0225 
6.7834 + .0389 
6.7694 .0121 
2.1120 + .0566| 
STANDARD DEVIATION. 
1.9561+ .0661 
2.4141 + .1187 
2.0138 + .1960} 
| 
0.4029 + .0136 
4015+ .0197 
-3508 + .0341 
-4001+ .0107 
0.3213 + .0108 
-3231+.0159 
-2824+ .0275 
-3200 = .0086 
1The numbers are, respectively, 202, 95, 24; 321. 
Vaitupa Valley. 
Proportions. 
Dp. ct. 
74.6558 .1235 
74.2766 + .1796 
75.1666 + .3502 
74.5820=+ .0981 
2.5834 .0873 
2.5812+.1270 
2.5440 + .2476 
2.5908 + .0694 
Length aper- 
ture + length 
shell, propor- 
tions. 
p. ct. 
52.7663 + .0833 
52.7871 .1195 
52.4167 +.2780 
52.7461 + .0666 
Tooth, index.! 
2.3466 + .0469 
2.3790 + .0682 
2.5834 .1313 
2.3739 + .0372 
1.7434+ .0589| 0.9892 + .0332 
1.7174 .0845 
2.0190 + .1966 
1.7571+.0471 
-9860 + .0482 
-9538 + .0928 
-9877 = .0263 
In so far 
as some shells of this and of other crassa colonies display this feature, it may be said 
that crassa is dentated; but it is by no means true, as Garrett unqualifiedly states 
(p. 220, this memoir) that all shells possess the pillar tooth. ‘The full array for the 
Vaitupa series is sufficient to establish the point that the tooth is a morphological 
feature of the colony but not one displayed by all of its constituents. 
TaBLeE 225.—Partula otaheitana crassa. 
Vaitupa Valley. 
Toortu. 
Series. None Trace. Tooth. Large. | Very large.| Total. 
Pheatstriataaeeee eee 51 50 86 10 5 202 
confluens.......... 19 34 32 7 3 95 
cestatatmrienla racine 3 8 10 2 1 24 
FN Se AERA GO NTE MICS AO. 73 92 128 19 9 321 
FEcuNDITY. 
. No. of} Per cent | No. of} No. of} Total | Average | Average 
Series. Records. R 3 2 
gravid.| gravid. | eggs. |young.|contents.|for gravid.| for all 
phea striata..... 200 150 | 75.0 252 | 105 357 2.38 
confluens.. . 94 2 ORO 136 33 169 2.35 
COMA 60000000 24 21 87.5 34 11 45 2.14 
All igs paphes Sis Seon 318 243 76.4 422 149 571 2.35 
