In addition , to these three characteristics , there are also two other shell characters , shell thickness and shell smoothness , which are not easily studied by quantitative analysis 除這三種殼因子外,還有兩個難以定量比較分析的貝殼形態(tài)特征,即殼厚度或堅硬度和光滑度。
The results of factor analysis showed that the following three shell factors are independent , and that there are no correlations among them : shell size , shell flatness and protoconch whorl number 因子分析結(jié)果顯示殼大小、殼扁度及原殼螺層數(shù)三種殼因子是相互獨立的,它們之變異互不相關(guān)。