ACHATINELLA CURTA. 257 



vex; columellar fold central, white, strong; aperture trun- 

 cately auriform, white within; peristome thickened within; 

 with external margin unreflected, arcuate, acute ; columellar 

 margin dilated, adnate, white ; parietal margin wanting. 

 Length 16, breadth 10%, length of body-whorl 11% mm. 

 Average weight 4.7 grains. 



' Var. &, without bands. Var. c, with one black spiral line. 

 Var. d, with two broad black bands.' (Gulick) . 



Oahu : Kalaikoa, Ahonui, Wahiawa and Helemano, on trees 

 and shrubs. J. T. Gulick. 



"In Wahiawa, which is the metropolis of the species, var. 

 a is most abundant; var. b is more widely diffused, being 

 occasionally found in each of the above-mentioned localities ; 

 vars. c and d are very rare ; the former approaches A. con- 

 tract a Nob., and the latter passes into an unusual variety of 

 A. emersonii Newc.' (Gulick}. 



A. delta is a connecting form between reevei and curta, 

 comparable to the streaked form of curta from Kawaiholona, 

 and probably not more deserving of a varietal name than that. 



Mr. Gulick 's type of delta is a Wahiawa shell closely agree- 

 ing with pi. 45, figs. 20-22, from the same lot, of which over 60 

 specimens are before me, No. 92,619 A. N. S. The prevailing 

 shape is that of A. curta, but it varies to longer shells, like 

 livida. The color-forms figured on pi. 45, figs. 17-22 are from 

 one colony. 



(a) The ground color of the typical form is white above, 

 on the last whorl shading from white at the suture to pinard 

 yellow on the base, the yellow area often much reduced. The 

 sutural margin is white, followed by a band of violet plum- 

 beous, grayish lavender or ecru-drab obliquely streaked with 

 white. Above and below the periphery there are similar 

 bands. Sometimes the lower band is wanting, and the others 

 reduced to lines; and rarely the dark color of the bands ex- 

 tends in streaks over the whole banded portion, much as in 

 reevei, or in the rare variety of curta from Kawaiholona. 

 (&) The other common color-form has a ground of yellow, 

 fading above the periphery to white, or rarely continuous 

 over the whole last whorl. It has no dark bands, or rarely 



