ACHATINELLA CURTA. 253 



Typically distinct from livida and recta by the shorter spire 

 and the short, swollen, last whorl ; also differing in the color- 

 patterns; yet there are forms which one cannot satisfactorily 

 classify. PL 45, fig. 1 is a copy of the type figure. 



There are three color-forms which have been described as 

 species under the names curt a (yellow with a chestnut or 

 chestnut-black subsutural band), rhodoraphe (yellow with a 

 pale pink subsutural band), and undulata (pale ochraceous 

 buff with many irregular tawny stripes and sometimes a black- 

 ish peripheral band). There are also a number of other pat- 

 terns as noted below. The curia and rhodoraphe patterns 

 often occur in the same colony, and curta colonies sometimes 

 contain both rhodoraphe and undulata if I may judge by 

 Wahaiwa series in the Cooke collection. Chiefly rhodoraphe 

 occurs in Ahonui (Gulick coll.), at the eastern limit of the 

 species, and pure curta has been taken in Laie, unaccom- 

 panied by other patterns. There are some ' ' blends ' ' between 

 these three patterns, but as a general rule, good segregation 

 prevails in hybrid colonies. 



Northwestward curta is replaced by dimorpha, in which the 

 shell is usually more lengthened. 



Ahonui (pi. 45, figs. 2, 3, coll. by Gulick). Most of the 

 specimens are yellow with a pink zone below the suture 

 (rhodoraphe). The pink zone begins on the last embryonic 

 whorl as an ochraceous band. The largest shell is 17 mm. 

 long. There are also a few shorter shells of typical curta 

 form, yellow fading to white at the summit, without a sub- 

 sutural band. 



Wahiawa (pi. 45, figs. 10, 11, 3d gulch of Wahiawa, coll. by 

 Kuhns). Last whorl or two apricot yellow, with a chestnut- 

 black band below the suture, edged below with orange rufous, 

 sometimes followed by whitish. Embryo all white or with a 

 brown hand extending to the apex. The same curta pattern is 

 in the Cooke collection from low ridges and valleys of Wahi- 

 awa, together with specimens without sutural band, and others 

 with it faint and narrow, the embryonic whorls with an ochra- 

 ceous band, the body-color varying from yellow to ochraceous 

 tawny. Also rhodoraphe like those of Helemano, or without 



