PARTULA GIBBA, GUAM. (ee, 
STATISTICAL CHARACTERS OF THE COLOR-CLASSES. 
The final task in the analysis of Partula gibba is to review the statistical record 
of the several color-classes belonging to the several local series throughout the 
island. Its first purpose is to complete the empirical description of the material, 
thus to establish a basis for any future studies of like nature. The second object 
is to discover whether distinctive characters of size or form accompany one or 
another of the modes of coloration; at the outset it may be stated that no such 
correlation is disclosed. 
Northeast Region.—The three representative collections from this territory are 
somewhat widely separated geographically, and hence it is not surprising that they 
should differ in color composition as they do. ‘Tarague is one of the two places 
where unicolor was found; the close relative bicolor appears in all three localities, 
but with only one example at Santa Rosa. While mitella-rubra and phaea exist 
in all, it is strange that the more basic type of mitella is absent from Asados. 
TABLE 31.—Partula gibba, Guam. Northeast Region. 















































Lip. Tooth. 
Series. No. 
White. Faint Yellowish. | None. Trace. | Small. 
yellowish. 
Tarague: WHICOIGL Axe aa aso ets os eee 80 66 7 7 80 
Bicolor= 25m rt teins ae fe sole ae cink 82 17 i2 53 82 
mite) lai Some tds nis aan a eater 102 48 19 35 99 2 1 
Baa Cel TU TR catetee cos &o,02 ee eae ane 19 19 17 2 
Rhee cn eee ans ee ae nc eet cee 9 7 2 9 
LEMS SEE: 2 eR a eS ee oe 292 157 40 95 287 4 1 
SSIES RCSA SU DICOIORS oh igiaie acs, ase isreha aren 98s euaw nse a.ous ele 1 1 dese ah Bye 1 arate area 
ct LSE, Ree 2 aii eran ne ee 25 6 4 15 15 vi 3 
PNMAAFUDTAs Gare hots vik 6s 6's Care xarene 45 32 13 bars 33 12 leh 
phea-purpureasccssetoe ss co aie ence ae 1 1 Ree eas one 3 Seas 1 
LE rete ere FS MEV OAAOR Paola eos Ue 40 17 15 49 19 4 
Asados: icolors sce ee as Sra oe nee 4 4 3 Stil Fi 1 
WI COM MAFUD TA gales tice face eens nein os 65 62 2 1 RBl 17 L7 
Dhea-rubraé dss. uccee seh ae eases tie 34 14 13 Z 20 9 5 
PDhea-PuUrpurea.. sc. 5 ues. ess se Paes 37 17 11 9 23 11 3 
/NU beste PRN Gin AER © MNO ie 140 93 26 21 77 37 26 





Taking first the Tarague series, the notable points disclosed by the statistics 
(table 30) are the consistent agreement of unicolor and bicolor, the smaller absolute 
measures of the mitella-rubra class, and the larger dimensions of the phea group; the 
last named is quite as aberrant in proportionate characters as it is in the direct 
measures. In relation to the color of the lip (table 31) the important point is that 
the yellowish or yellowish-brown tinge is exhibited mainly by bicolor and mitella 
shells. As in the former there is some correlation between the depth of color of 
the revolving bands and the degree to which the lip is stained, it would be expected 
that in the clouded mitella-rubra shells the lip would be more frequently tinged 
than inthe simpler mitella, but the fact is that the lip is universally white in mitella- 
rubra. The deeply-placed callus or tooth is very rarely developed in shells of this 
association. 
