116 PARTULINA DUBIA, OAHU. 



but having examined all of the specimens found, I think the 

 evidence against that hypothesis. 



Achatinella platystyla Gulick, pi. 26, fig. 11, and pi. 50, fig. 

 17, is a peculiar color-form of dubia, described from a single 

 shell. The surface is a good deal pitted, but it was evidently 

 a " live " shell, and an old one. The surface is entirely 

 eroded to the middle of the fourth whorl. What cuticle re- 

 mains on the next two whorls is pecan-brown with creamy 

 streaks, and fading upwards. The last whorl is light buff in 

 the upper third, shading downwards into pecan-brown, which 

 is streaked with a lighter tint and 'has very indistinct spirals 

 of the darker shade. The color is almost exactly that of some 

 specimens of Achatinella glabra. The surface shows faint 

 spiral striation, which becomes stronger upwards, as usual in 

 P. dubia. The aperture, lip and perforation are exactly as 

 in Main Range dubia. The lip has a faint yellow tint, deeper 

 at the edge. Length 20, diam. 10.3, aperture 8.4 mm.; 6> 

 whorls. 



The unique type of platystyla was collected by Mr. Gulick 

 in Kawailoa. It is no. 25 of his type collection, Boston So- 

 ciety of Natural History. I have given two views of this 

 specimen. 



Achatinella pexa Gulick, pi. 26, fig. 12, is certainly a sinis- 

 tral specimen of A. dubia. The unique type specimen, no. 

 26 of Gulick 's type collection, coll. Boston Society of Natural 

 History, is figured. The shell has the texture and thin sub- 

 stance of dubia. The ground-tint is between light buff and 

 white. It appears in spirals and obliquely axial streaks, leav- 

 ing rather wide interrupted streaks of vinaceous pink, here 

 and there darker. There is a brown line at the periphery 

 and a group of three around the umbilical region. The early 

 whorls are eroded, but traces of alternate light and darker 

 stripes can be made out on the last embryonic whorl. The 

 glossy surface is engraved with rather distinct close spirals, 

 as in P. dubia. The lip expands a little. Aperture, lip and 

 perforation are as usual in P. dubia; the lip having a pale 

 yellowish-brown edge and slight thickening. Length 19, diam. 

 10.7, aperture 9 mm. ; 6^ whorls. 



