76 LEPTACHATINA, S.-G. LABIELLA. 



species in Pease's collection at Cambridge. A few have an 

 additional whorl and measure 13.5 x 4.9 mm. 



Specimens from Kumuwela are slightly more obese and for 

 the most part lighter colored. One with 8 whorls measured 

 12.8 x 5.3 mm. 



Those from Halemanu are somewhat smaller. A well de- 

 veloped shell with 8% whorls measured : 11.0 x 4.5 mm. 



A single shell from Ekaula is quite slender for this 

 species ; it has 9 whorls and measures 12.8 x 4.3 mm. 



Subgenus LABIELLA Pfeiffer, 1854. 



Labiella PFR., Malak. Blatter, 1854, p. 142 ; P. Z. S., 1855, 

 p. 7. HAETMAN, P. Ac. Phila., 1888, p. 41. H. & A. ADAMS, 

 Gen. Recent Moll., ii, p. 139. GULICK, P. Z. S. London, 1873, 

 p. 91. PEASE, P. Z. S., 1869, p. 651. 



Labiella was proposed by Pfeiffer as a section of Achati- 

 nella for A. labiata, with the following diagnosis "Shell ob- 

 long, solid; columellar fold twisted; lip obtuse, thickened, 

 with a tooth-like callosity within the dextral margin." 



Hartman followed Pfeiffer in considering Labiella as a 

 section. H. and A. Adams raised Labiella to subgeneric rank. 

 Gulick (1873) transfered Labiella to a section of Leptacha- 

 tina. Pease raised Labiella to the rank of a full genus. He 

 enumerated twelve species, four of which (crassilabriim, 

 ellipsoidea, albolabris and subrostrata) belong to the genus 

 Amastra. 



There are but four species (three from Oahu and one from 

 Maui) which can properly be included in this subgenus. The 

 spire in these species is slightly concave in outline ; the upper 

 whorls are closely coiled and increase slowly; the denticle 

 of the outer lip is present in three of the four species. This 

 character is almost or entirely lacking in lagena but as this 

 species is otherwise closely related to labiata it is best to 

 include it in the same subgenus. The denticle was lacking 

 in the type specimen of lenta, but there is a specimen in Mr. 

 Baldwin's collection in which this character is clearly in- 

 dicated. 



