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PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. 41. 



rounded. Aperture very oblique, large, broadly oval ; posterior angle 

 obtuse; outer lip thin; columella very oblique, slightly curved, inner 

 lip partly reflected over the base; parietal wall covered with a thick 

 callus, which is free at the edge and renders the peritreme complete. 

 The type (Cat. No. 213453, U.S.N.M.) has four and one-half post- 

 nuclear whorls and measures: Length 2.9 mm., diameter 1.3 mm. 

 It was collected at Atka Island, Alaska. 



Specimens examined. 



Cat. No. 



Locality. 



Number of 

 specimens. 



213453 (figured type) 



213454 :.... 



213455 



161103 



Atka Island, Alaska 



Outer Beach, Kyska Island, Alaska 



Constantine Harbor (beach), Amchitka Island, Alaska 

 Kyska Island, Alaska 



NODULUS ASSER Bartsch. 



Onoha asser Bartsch, Nautilus, vol. 23, 1910, No. 11, p. 138, pi. 11, fig. 9. 



Shell elongate-conic, bluish white, semitranslucent. Nuclear 

 whorls one and one-tenth, smooth, a little less elevated than the suc- 

 ceeding turns. Post-nuclear whorls very high between the sutures, 

 overhanging, moderately rounded, appressed at the sum- 

 mit. The preceding whorl shines through the summit of 

 the succeeding turn and gives this the appearance of hav- 

 ing a double suture. Sutures well impressed. Periph- 

 ery of the last whorl well rounded. Base moderately 

 prolonged, weU rounded. Entire surface of spire and base 

 marked by closely placed, exceedingly fine, microscopic, 

 spiral striations. Aperture very broadly ovate; poste- 

 rior angle obtuse; outer lip thin; peritreme complete. 



The type (Cat. No. 208434, U.S.N.M.) 



was collected by Dr. Fred Baker at Port 



Graham, Alaska. It has four and a half 



whorls and measures: Length 2.2 mm., 



diameter 0.9 mm. This species is nearest related to 



Onoha cerinella Dall, from which it is distinguished 



by its lesser size and more delicate structure. 



NODULUS KELSEYI, new species. 



Shell small, very slender, cylindro-conic, translucent, 

 white. Nuclear whorls two, strongly rounded, smooth. 

 Post-nuclear whorls rather high between the sutures, 

 well rounded, very narrowly shouldered at the summit 

 and lightly constricted a little anterior to the summit, marked by 

 fine lines of growth and exceedingly fine, spiral striations. Suture 

 moderately constricted. Periphery of the last whorl and the long 



NODU- 



FlG. 2 



LIJS ASSEK. 



Fig. 3.— NODU- 

 LUS KELSEYI. 



