124 ACHATINELLA ABBREVIATA. 



water, or too prolonged soaking, changes the vivid green color 

 -to a dirty olive-brown. The western extreme of its range is 

 (or was) in eastern Nuuanu, near the southeastern edge of 

 the new dam, where Mr. Spalding found five immature speci- 

 mens of the profusely-banded form (no. 1817 of his collec- 

 tion), possibly washed down from Konahuanui. 



PI. 31, figs. 1, la, 5, 5a ? Palolo, are from Gulick shells. The 

 others, figs. 2 to 4<i, are from material collected recently. A 

 lot from the northwestern ravine of Palolo varies from many- 

 banded to black (pi. 31, figs. 4, 4a-4d). There was also one 

 shell all green except the brown summit. Figs. 3&, 4<i, 5 and 

 5a are rare color-forms. 



The shell is obesely-ovate, very glossy, showing faint spiral 

 striation on the lower, clear but very fine incised lines on the 

 early whorls. The lip is acute, not thickened within or but 

 slightly so. All I have seen are dextral. 



1. The typical color-pattern as figured by Reeve is yellow 

 above the periphery, green below it, the colors separated by a 

 peripheral chocolate band. The suture is bordered above and 

 below by chocolate bands. Near the summit the yellow ground 

 gives place to reddish-brown, becoming dusky or purplish- 

 brown at the apex (pi. 31, fig. 2). This pattern occurs in 

 Palolo valley together with the following, the inter gradation 

 being complete throughout the series. 



2. Similar to no. 1, but having additional chocolate lines 

 and bands (pi. 31, fig. 2a, Palolo; figs. 3, 3, Palolo- Waialae 

 ridge), which sometimes almost cover the yellow and green, 

 ground. 



3. Same as no. 2, but without green (pi. 31, figs. 4, 4&), or 

 the bands may be confluent, leaving yellow bands at periph- 

 ery, suture or both (fig. 46). 



4. Last whorl black or nearly so, landless, the color becom- 

 ing lighter upward, dark again at the summit (pi. 31, figs. 4c, 

 4d) . This is the form called A. bacca by Reeve. A. abbre- 

 viata and A. bacca are therefore merely selected patterns in a 

 continuous series of variations occurring in the same colony. 

 Figs. 4 to 4:d are from a northwestern ravine of Palolo, next 

 to the Manoa ridge, coll. by Pilsbry. 



