296 AMASTRA, MAUI. 



Achatinella mastersi NEWC., P. Z. S., Lond., 1853, p. 153 f 

 pi. 24, fig. 67 (1854) ; Ann. Lye. N. H. of N. Y., vi, 1858, p. 

 332 (animal). Laminella mastersi Nc., W. G. BINNEY, Ann. 

 Lye. N. H. of N. Y., x, p. 335, pi. 15, figs. 7, 9-11 (jaw and 

 teeth) ; Ann. N. Y. Acad. Sei., iii, 1884, p. 98, pi. 16, f. E 

 (jaw) ; pi. 6, fig. E (teeth). 



Newcomb's description is given above and his figure is 

 copied, pi. 43, fig. 12. The original locality was Maui. In 

 his paper of 1858, where the animal is described, Newcomb 

 states that " A. mastersi is an inhabitant of Molokai, and is 

 sparsely found on Maui." It is evident that more than one 

 form was included by Newcomb in his definition of the species. 

 The form selected for his figure is, as Mr. Thwing has im- 

 plied, the bicolored race from Makawao, in East Maui. A\ 7 hile 

 this does not agree with all of the description, it was evi- 

 dently regarded by Newcomb as a typical mastersi. He 

 records other species from Makawao, and this was doubtless 

 the type locality of mastersi. 



The shell is glossy, the upper half of the last whorl rich 

 chestnut, lower half yellow, sipire brown, the embryonic 

 whorls reddish or dull-purple. Other shells have the last 

 whorl chestnut, spire either a lighter or a darker shade. 

 There is no outer layer of dark cuticle. The outlines of the 

 spire are convex. The second embryonic whorl is strongly 

 eostate, with a carina which is concealed at the suture. Fol- 

 lowing whorls are irregularly plicate below the suture, the 

 last whorl well rounded, not malleate. Aperture white, the 

 lip acute, not thickened within. Columellar fold small and 

 oblique. Axis imperforate. 



Length 18, diam. 10 mm. ; 6 whorls. 



Length 18, diam. 9.5 mm. 



In another color-form the shell is pale-yellow, spire gray- 

 brown (pi. 43, fig. 17). 



Typical A. mastersi, as restricted to this form, is special 

 to East Maui, occurring on the northeastern flank of Halea- 

 kala, on one of the routes to the crater. A more globose 

 form, length 16, diam. 10 mm., with 5!/o whorls, occurs at 

 Honomanu, inland from Keanae, north of Haleakala crater. 



