88 PARTULINA, LANAI. 



species because in the large series of both species seen the in- 

 tergrading specimens are comparatively very rare. Nearest to 

 Koela the white form occurs, further along the ridge the 

 darker forms. Either sinistral or dextral forms may pre- 

 dominate in different colonies. Fig. 13 is copied from New- 

 comb's type figure. Figs. 1-4, 15 are from specimens taken 

 by Mr. Thaanum. 



45a. Var. hayseldeni Baldwin. PL 21, figs. 5 to 12. 



" Shell sinistral, minutely perforated, rather solid, ovately 

 conical, apex subacute ; surface shining, marked with delicate 

 incremental striae, and under a lens exhibiting very close, 

 minute, decussating spiral lines; embryonic whorls faintly 

 cross-lined. Color generally of a uniform reddish-brown; 

 sometimes the coloring of the middle portion of the whorl 

 shades into white on the apical whorls, and in some examples 

 a white line revolves below the suture. Whorls 5*/2, slightly 

 convex, narrowly margined above, the last carinated or angu- 

 lated at the periphery, the angle becoming almost obsolete 

 (towards the aperture; suture distinctly impressed and often 

 margined above by the continuation of the peripheral keel. 

 Aperture oblique, subovate, white within with a pinkish tinge ; 

 peristome white, rather obtuse, thickened within, the basal 

 and columellar margins slightly reflexed; columeJla termin- 

 ating in a strong, flexuous, white fold. Length 17*/2, diam. 

 10 mm. 



11 Animal when extended in motion longer than the shell. 

 Mantle slate color with a brown band encircling the outer 

 edge. Foot above and below almost white with a yellowish 

 tinge. Tentacles white tinged with slate " (Baldwin). 



Lanai (Walter H. Hayselden) ; Lanaihale, near highest 

 point of mountain (Perkins, Thaanum). 



Partulina hayseldeni BALDWIN, Nautilus, x, p. 31, July, 

 1896. Achatinella (Partulina) hayseldeni Baldwin, SYKES, 

 Fauna Hawaiiensis, p. 313, pi. 11, f . 2. 



1 This species is allied to P. semicarinata Newc., which is 

 found in another district of the same island. The latter is a 

 light straw-colored, more conical, and invariably dextral 



