

AMASTRA. 49 



whorl smooth, next whorl having rather coarse, arcuate riblets, 

 and carinate above the suture; the following whorl more 

 closely and sharply rib-striate (pi. 3, fig. 15). Neanic whorls 

 carinate, the carina showing above the suture on some of the 

 whorls, becoming obsolete on the penultimate whorl; last 

 whorl more or less swollen. The outer lip has a white internal 

 thickening ; columellar lamella moderately strong, oblique. 



Length 10, diam. 5.7, aperture 4 mm. ; 6*4 whorls. 



Length 10.2, diam. 5.5, aperture 4.3 mm. ; G 1 /^ whorls. 



Length 9.3, diam. 5.6, aperture 4 mm.; 5% whorls. 



West Maui: gulch to the right of Maunahoomaha, above 

 Lahaina, D. Thaanum, 1913. Cotypes in A. N. S. P. and 

 Bishop Mus. Also reported by Mr. Thaanum from Mt. Helu, 

 Honokawai gulch, Moomuku and Honokohau. 



This form has coarser ribs on the embryonic whorls than 

 any of the related species, and the second embryonic whorl is 

 flatter. The shell is larger and much more solid than A. sub- 

 soror. As in that, there is a small pale tract around the colu- 

 mella, the rest of the shell being very dark brown. 



Hawaiian Amastras. 

 A. MELANOSIS (Newcomb). PI. 1, fig. 17. 



Vol. XXI, p. 312. Having examined a paratype from 

 Newcomb 's collection (pi. 1, fig. 17, no. 30,014 Cornell Univ.) 

 we are satisfied that his melanosis was based upon immature 

 shells, lacking almost or quite a whorl of maturity, and cor- 

 responding exactly with the immature stage of the shells 

 figured in Vol. XXI, pi. 47, figs. 1, 2. These shells were 

 from Mr. Baldwin, labeled Hamakua. Probably obtained 

 by him from Mr. Homer. Their exact locality could doubt- 

 less be traced. Newcomb 's label however says "Mauna Loa, 

 Hawaii." Very little importance is to be attached to this, 

 since Newcomb himself did not collect the shells, and it is 

 very doubtful whether such an Amastra occurs on Mauna 

 Loa unless so far down as to rob the term of any definite 

 geographic significance. At all events, the Hamakua shell 

 appears to be the typical form of A. melanosis. 



Dr. Newcomb 's original figure, copied in Vol. XXI, pi. 47, 



