LAMINELLA, MOLOKAI. 351 



.ca. p. 84, pi. 8, f. 17, and dextral form, f. 18. GULICK, Evo- 

 lution, Kacial and Habitudinal, 1905, p. 38, pi. 1, f. 7. 

 A. citrina inhabits a narrow area perhaps 6 or 7 miles long, 

 :>n the ridge of the island south of the northern peninsula. 

 It is therefore rather widely separated from the area of the 

 closely related A. helvina, so far as present information goes. 



L. citrina is distinct from L. venusta variety semivestita 

 by the larger size, when other characters fail. Pease (P. Z. 

 S., 1869, p. 652) unites it to venusta as a plain variety. Typi- 

 cally it is spotless and very pale yellow throughout (primrose 

 yellow of Ridgway's Nomenclature of Colors), the columella 

 white. The type, and some specimens collected by Newcomb 

 and Gulick, was weakly angular in front (not " subcarinate " 

 as Pfeiffer says), by retention of a feature of immaturity; 

 but most adult shells seen have the last whorl well rounded. 

 The contour varies a good deal, as usual. 



Two of these typical subangular shells are figured and 

 measured below. Five out of the lot of six received from 

 Newcomb are more or less distinctly biplicate, the others hav- 

 ing the upper fold bifid. A few shells in this and another lot 

 received from Newcomb have small olive dots or flecks scat- 

 tered on the first two neanic whorls. 



PI. 50, fig. 2. Length 17.5, diam. 8.1 mm. ; 6% whorls. 



PI. 50, fig. 1. Length 16, diam. 8 mm. 



Three specimens from the Mighels collection, procured 

 through Thomson by the collection of the Portland Society 

 of Natural History, are of the immaculate form commonly 

 accepted as citrina. 



In a large series received from Gulick, about one-third 

 have the neanic whorls variously dotted, the dots sometimes 

 scattered along the suture which is margined below (pi. 50, 

 figs. 4, 5, 8). The rest are plain throughout, Columella bi- 

 plicate. The only dextral specimen of citrina in the collec- 

 tion before me is dotted along the suture (pi. 50, fig. 4), and 

 occurred in a lot of citrina otherwise sinistral and plain. 

 Borcherding has figured a plain dextral specimen from Ka- 

 hanui, in the central part of the island. 



Several lots in the Cooke collection, received from Baldwin 



