206 ACHATINELLA STEWARTII. 



A. stewartii differs from A. s. producta by being narrower, 

 the last whorl shorter and a little compressed, the spire more 

 turrited, and the suture always bordered with black. It dif- 

 fers from fulgens by lacking white bands, by the dark suture, 

 and various peculiarities of pattern more readily appreciated 

 than described. A. vulpina and A. stewartii are very inti- 

 mately related, but in general, A. stewartii is either sinistral 

 or dextral, larger, more turrited, and when melanistic the 

 dark hue is in bands. A. vulpina is smaller, more oblong- 

 ovate, the melanism is sometimes more generally diffused; 

 typically it has no dark sutural band, and is sinistral (with 

 rare exceptions). 



So far as I know, all stewartii colonies are hybrids of sev- 

 eral elementary patterns, as follows: 



1. From deep colonial buff to malachite green, with dark su- 



tural band and columellar patch. PI. 38, figs. 1, 2-3. 

 Stewartii pattern. 



2. Olive-ocher or greenish, closely streaked with cinnamon, 



and with sutural and columellar black bands. PI. 38, 

 fig. 4. Similar to the dunkeri form of producta. 



3. Ground-color like either of the above, but having four black- 



ish bands. PI. 38, figs. 4a to 6a. Johnsoni pattern. 



Palolo, in the head of a makai branch, in the western ravine 

 on the Manoa ridge, pi. 38, figs. 1 to 2& coll. by Pilsbry; fig. 

 3, coll. by Wilder, is a prolific locality for all of the above- 

 described color-forms. Most of the specimens are sinistral. 



Towards the main range or "mauka" from the well-known 

 stewartii ravine on the Palolo-Manoa ridge, Mr. Spalding 

 found a colony which unites stewartii and fulgens. It con- 

 tains the following patterns : stewartii forms 1 and 3, tri- 

 lineata, diversa and varia with dark sutural line. All are 

 sinistral. This has the appearance of a fulgens (varia) 

 colony hybridized with stewartii. Mr. Thurston has collected 

 stewartii-diversa-plumata patterns in the same region. 



In north-eastern ravines of Manoa the patterns are simi- 

 lar to those of Palolo ; typical stewartii, streaked, and banded, 

 but most of the shells are dextral (pi. 38, figs. 4, 4a, Cooke 



