108 AURICULELLA, MAUI. 



b l . Shell solid, longer, the parietal callus often thick pos- 

 teriorly, but not so distinctly tuberculiform. 



uniplicata, no. 26. 



26. A. UNIPLICATA Pease. PI. 18, figs. 8 to 16. 



"Shell solid, perforate, dextral or sinistral, elougately 

 ovate ; spire conic, hardly obtuse ; suture impressed ; whorls 6,. 

 flatly convex; longitudinally thinly striated; aperture hardly 

 oblique, truncately oval; lip thickened, with the margins 

 joined by a callus ; parietal lamella thin ; columella simple, not 

 plicate ; yellowish, or brownish, banded with brown. Length 

 7, diam. 4 mm." (Pse.). 



West Maui (Baldwin) : lao Valley, Honokohau and Waikee 

 (Thaanum), Maunahooma (Cooke). 



Auriculella uniplicata PEASE, Journ. de Conchyl., xvi, 1868, 

 p. 344. SMITH, P. Z. S. Lond., 1873, p. 88, pi. 10, fig. 21.- 

 PFEIFFER, Mon. Hel. Viv., viii, p. 211. ANCEY, Bull. Soc. 

 Malac. France, vi, 1889, p. 222. SYKES, Fauna Hawaiiensis, 

 ii, Moll., p. 378. Not of BORCHERDING, Zoologica, part 48 2 , p. 

 138, pi. 9, figs. 14, 14a. 



Next to A. auricula this is the most variable species of the 

 genus. Some large, solid specimens collected by Mr. Thaanum 

 at Honokohau, West Maui, measure 9 mm. in length by 4.6 

 mm. in breadth. Mr. Sykes has reported this species as com- 

 ing from Molokai. I feel doubtful as to his identification. 

 Borcherding's specimens are probably a form of A. brunnea 

 Smith. 



This West Mauian species differs from A. crassula by the 

 someAvhat more lengthened contour and the less developed 

 thickening at the posterior angle of the aperture. In unipli- 

 cata the parietal callus forms a ridge, when strongly devel- 

 oped, while in crassula it rises in a rounded or oval tubercle. 



The form called A. jucunda Smith (Ann. Lye. Nat. Hist, of 

 N. Y., x, 1874, p. 332) was never defined in any way. Ac- 

 cording to specimens from Gulick's collection (pi. 18, figs. 6, 7, 

 Lahaina, no. 92708 A. N. S. P.) it is a form of uniplicata with 

 the parietal callus especially heavy, having some affinity to 

 A. crassula. 



