NO. 2193. WEST A3IERICAN MARINE M0LLUSKS—BART8CH. 6Y7 



ALVANIA BARTOLOMENSIS. new species. 



Plate 46, fig. 4. 



Shell very elongate ovate, pale yellow, slightly mottled and 

 streaked with rust brown. Nuclear whorls 2^, smooth, well rounded. 

 Postnuclear whorls well rounded, appressed at the summit, marked 

 by incised spiral lines which are of somewhat irregular strength and 

 spacing. Of these lines 17 occur between the summit and the pe- 

 riphery of the last whorl. The axial sculpture is reduced to mere 

 lines of growth. Suture moderately constricted, periphery of the 

 last whorl well rounded. Base moderately long, well rounded, 

 marked by incised spiral lines which are of equal strength and spac- 

 ing. Aperture irregular, decidedly effuse at the junction of the outer 

 and basal lip; slightly channeled anteriorly; posterior angle acute; 

 outer lip thin at the edge, thick within. Inner lip short, thick, 

 slightly curved, reflected over and appressed to the somewhat atten- 

 uated base; parietal wall covered with a thick callus, which renders 

 the peritreme complete. 



The type. Cat. 2G8742, U.S.N.M., was collected by the United States 

 Bureau of Fisheries steamer Alhatross, in shallow water in San Bar- 

 tolome Bay, Lower California. It has 4J postnuclear whorls and 

 measures — length, 4.2 mm. ; diameter, 1.9 mm. 



ALVANIA KYSKAENSIS. new species. 

 Plate 46, fig. 6. 

 Shell elongate ovate, pale brownish yellow. Nuclear whorls one 

 and one-half, well rounded, marked by very slender spiral striations 

 and exceedingly fine incremental lines. Po^nuclear whorls strongly 

 rounded, weakly shouldered at the summit, marked by slender axial 

 riblets which are somewhat sinuous and slightly retractively slanting. 

 Of these ribs 24 occur upon the first, 26 upon the second, and 40 upon 

 the penultimate turn ; these are about one-third as wide as the spaces 

 that separate them. In addition to the axial sculpture, the whorls 

 are marked by four spiral cords, of which the first, Avhich is about as 

 far from the summit as it is distant from the second, is very weak 

 on the first two whorls, but on the last assumes almost the strength 

 of the other three cords. The other three cords are of equal strength 

 and spacing. The junction of the axial ribs and the spiral cords, 

 which are a little stronger than the ribs, form weak nodules, while 

 the spaces inclosed between them appear as well impressed, squarish 

 pits. In addition to this sculpture, the entire surface is marked by 

 very fine incremental lines and numerous miscroscopic spiral stria- 

 tions, the two lending it a cloth-like texture. Suture strongly con- 

 stricted. On the last whorl the first basal keel makes its appear- 

 ance above the summit of the succeeding turn. Periphery of the 

 last whorl marked by a spiral sulcus about as wide as those separat- 

 ing the cords on the spire. Base well rounded, marked by seven equal 



