IO SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 98 



lines. Nuclear whorls exceedingly small, apparently smooth. The 

 early postnuclear turns have 4 deep spiral grooves, which are of equal 

 width and which separate the intervening spaces into 5 equal rounded 

 cords, the first of which is at the summit. On the succeeding turns 

 the incised spiral lines hecome less strong, and the spaces between 

 them are broad, slightly rounded zones. Of these incised spiral 

 grooves, 6 are present between the summit and the suture on the last 

 whorl, and 4 more between the suture and the basal angle. In addition 

 to this the whorls are marked by fine incremental lines and closely 

 crowded microscopic spiral striations. Suture moderately conspicuous. 

 Periphery obtusely angulated. Base marked by 8 equal and equally 

 spaced incised spiral lines and the continuations of the same finer 

 sculpture mentioned for the spire. Aperture broadly ovate, somewhat 

 effuse at the junction of the basal lip and columella, and decidedly 

 acute at the posterior angle ; outer lip strongly arched and thin. Oper- 

 culum moderately thin, corneous, having a little more than 3 whorls 

 with excentric nucleus marked by fine incremental lines. 



The type, U.S.N.M. no. 472547, a male, has 7.4 whorls and mea- 

 sures : Length, 1 1.8 mm. ; greater diameter, 8.2 mm. ; lesser diameter, 

 6.5 mm. It, and a series of specimens, U.S.N.M. no. 472546, were col- 

 lected at Clipperton Island "on rocks at the shore south of the landing. 



This species presents sexual dimorphism, the females being much 

 larger. Large old specimens are usually badly eroded and fail to show 

 the splendid color pattern displayed in the type. A large female has 

 5.3 whorls and measures: Length, 18.2 mm.; greater diameter, 11.8 

 mm. ; lesser diameter, 10.5 mm. 



This species is related to the Hawaiian Littorina pintado Wood, but 

 is easily distinguished from this by its darker color and by having the 

 spiral grooves less deep and more distantly spaced. 



It is named for Dr. Waldo L. Schmitt, its discoverer. 



HIPPONIX FIMBRIATA, n. sp. 



Plate 2, figs. 7-9 



Shell cup-shaped, i. e., irregularly broadly conic, pale yellow, cov- 

 ered by a pale golden-yellow, much fimbriated periostracum. Interior 

 porcelain white. The nucleus is very small consisting of a little more 

 than 1 whorl, which is well rounded and microscopically granulose. 

 The postnuclear part increases very rapidly in size and loses its coil- 

 ing, forming a broadly flaring cuplike structure, whose exterior is 

 marked by a series of concentric lamellae, whose edges are more or 

 less free and somewhat fimbriated. The ventral margin, i. e., peri- 



