AURICULELLA, OAHU. 99 



Auriculella tennis SMITH, P. Z. S. Lond., 1873, p. 87, pi. 

 10, fig. 27. PFEIFFER, Mon. Hel. Viv., viii, p. 213. ANCEY, 

 Bull. Soc. Malac. France, vi, 1889, p. 280. 



This shell is very closely related to A. castanea Pfr. It dif- 

 fers, however, in size, being more slender, slightly thinner, 

 and in having a minute perforation. In the young 2.6 

 mm. long, and up to about three-fourths grown, the lower 

 columellar lamella is very strongly developed. A. tennis var. 

 solida Anc. is A. castanea Pfr. This latter species is found in 

 the southeastern portion of the main mountain range of Oahu, 

 while the former is found towards the northwestern extremity 

 of the same range. Probably forms connecting the two species 

 may be found when the intermediate region has been suffi- 

 ciently explored. Some immature specimens are before us 

 from the summit of the Manana-Waimano ridge, taken from 

 axils of ieie. 



20. A. TENELLA Ancey. PL 19, figs. 7, 8. 



" Shell sinistral, ovately conic, pellucid, very thin, reddish 

 corneous or straw color indistinctly streaked with reddish 

 corneous; perforate, glossy, under a lens obliquely slightly 

 striated (except the somewhat obtuse apex). Spire regularly 

 conic ; whorls 7, regularly increasing, suture narrowly mar- 

 gined; the upper whorls more convex, the rest scarcely con- 

 vex ; the last larger, rotund, ascending slightly and for a long 

 distance at the end. Aperture slightly oblique, scarcely thick- 

 ened, nearly circular, emarginate above, with a minute la- 

 mella (lamella thin) on the ventral portion of the penultimate 

 whorl, emarginate at the insertion of the columella. Colu- 

 mella obliquely twisted-plicate within, plica sometimes slightly 

 bipartite, the upper part of the lip straight, then slightly ex- 

 panded, broadly dilated at the margin of the columella, thin. 

 Length 6, diam. 3, length of aperture 3.6 mm" (Ancey). 



Oahu: Waianae Mts. (Baldwin, Cooke) ; Western ridge of 

 Popouwela (Spalding, Cooke & Pilsbry). 



Auriculella tenella ANC., Bull. Malac. France, vi, 1889, p. 

 232. 



"This pretty species is related to diaphana Smith, and to 



