PARTULINA, SECTION PERDICELLA. 17 



kupaia). THWING, Reprint Orig. Descript. Achat. p. 134, pi. 

 3, fig. 5. 



Newcomb states that A. helena "is extremely limited in its 

 locality, which has been twice carefully searched by myself 

 without discovering larger specimens, dead or alive, that ap- 

 proached it in form. Several of the specimens contained young 

 in the oviducts.' It was taken " within the coil of the Ti tree 

 leaf, as it starts from the trunk. ' 



The shell is sinistral, perforate; summit obtuse. There are 

 fully 2J convex embryonic whorls, the initial half-whorl smooth, 

 the next two evenly, rather strongly striate spirally; last em- 

 bryonic whorl is variegated with broad, forwardly descending, 

 brown and white flames. The neanic and last whorls have a 

 much finer and very close spiral sculpture of minutely waved 

 or crinkled striae, and a variable pattern of zigzag streaks, inter- 

 rupted by a cream-white peripheral belt; the axis in a light 

 area. The outer lip is thin, columella very short, with a rather 

 strong callous fold, and broadly but shortly dilated. 



Length 11.3, diam. 6.7, aperture 5.3 mm.; 5J- whorls. 



Length 12.2, diam. 6.5, aperture 6 mm.; 5^ whorls. 



Fig. 3 represents a typical specimen. Five specimens from 

 Newcomb, and others from Baldwin, the University of Wiscon- 

 sin, Cooke collection, etcetera, examined. There is considerable 

 variation in details of color-pattern, as in all related species. 

 Sometimes the stripes on the later whorls are smeared or partly 

 defaced, reduced to indistinct streaks. Occasionally the whitish 

 subperipheral belt does not appear until near the end of the last 

 whorl (fig. 4, Cooke coll.), or it may be entirely absent (fig. 2). 

 The color of the peripheral band, like the ground-tint of the 

 shell, varies from whitish to yellow. 



Color var. balteata n. v. has a single brown belt at the peri- 

 phery, continuous or indistinctly interrupted, on a pale fleshy 

 or brown-tinted ground, the flames of the last embryonic whorl 

 faint (pi. 4, fig. 7). 



A pretty color-form in the Cooke collection has the periphery 

 occupied by a series of dark spots, oblique in one example, 

 chevron-shaped in another, the flammules elsewhere reduced 

 to weak streaks or spots (fig. 6). 



