326 LAMINELLA, OAHU. 



(when not deciduous), such as appears only in the latest 

 stage the latter part of the last whorl of the less evolved 

 forms. Such a highly accelerated color-pattern can hardly 

 characterize a primitive form. 



No phylogeny of the species can be suggested, in the ab- 

 sence of fossil or retarded recent forms, but the principal 

 forms seem to be related somewhat thus. 



duoplicata 



alexandri 



depicta 



helviina 

 semivenulata 



picta } f remyi 



bulbosa } ( tetrao 



i 



sanguinea gravida, straminea 



Diagram to show the affinities of Laminellae, picta being considered the 

 most primitive form. 



While the gravida and sanguinea groups of Oahu seem 

 very distinct, yet both are related to the picta group, which 

 has both white and pink-mouthed forms. 



SPECIES OF OAHU. 



The Oahuan Laminellas are isolated, having been separated 

 for a long period from the other forms, among which they 

 seem nearest to L. picta and bulbosa of Maui and remyi of 

 Lanai. Two species are confined to the eastern or Koolau 

 range, the other inhabiting the western part of the Koolau 

 range and the Waianse mountains. 



a. Shell ovate with light ground-color. 



b. Diam. more than % length ; cream- white, partly cov- 

 ered with deciduous dark cuticle. 19x11 to 28x15 

 mm. L. gravida, No. 1. 



6 1 . Pale flesh or pink, cuticle nearly all lost. 



< L. g. suffusa, No. la. 



b 2 . White or pale yellow, without noticeable dark cuticle ; 

 more turrite ; aperture not quite % length. 



L. straminea, No. 2. 



