130 PROCEEDINGS OF THE NATIONAL MUSEUM vol.87 



Type: CerodriTlia {Lissodrillia) schroederi, new species. 

 This subgenus recalls CerodriUia, but it is separated from that by 

 lacking the spiral sculpture on the spire, base, and columella. 



CERODRILLIA (LISSODRILLIA) SCHROEDERI, new species 



Plate 17, Figube 8 



Shell very small, elongate-turreted, milk-white. Nuclear whorls 2, 

 strongly rounded, smooth. Postnuclear whorls appressed at the sum- 

 mit, slightly rounded, marked by very slightly retractively curved, 

 broad, rounded axial ribs, which are as broad as the spaces that 

 separate them. Of these ribs 10 occur on the first, 11 on the second, 

 12 on the third, and on the last two-thirds of a turn they become 

 quite obsolete. These ribs are flattened on the first turn but become 

 slightly humped below the middle on the remaining turns. They 

 pass over the periphery and evanesce at the insertion of the columella. 

 The ribs and intercostal spaces are marked by scarcely perceptible 

 lines of groM'th. Base moderately long, marked by the feeble con- 

 tinuation of the axial ribs and inconspicuous spiral striations. 

 Columella without spiral cords. Aperture elongate-oval, decidedly 

 channeled anteriorly; outer lip with a profound sinus immediately 

 below the summit and a weak stromboid notch anteriorly; inner lip 

 covered with a heavy callus which extends over the parietal wall. 



The type, U.S.N.M. No. 630585, has 6.2 whorls and measures: 

 Length, 4.8 mm. ; greater diameter, 1.9 mm. It was dredged by the 

 United States Bureau of Fisheries steamer Albatross at station 2410 

 in 28 fathoms off Charlotte Harbor, Fla., on a bottom of fine white 

 sand and broken shells. 



The species is named for Lt. Seaton Schroeder, navigator on the 

 Albatross at the time this dredging was made. 



RUBELLATOMA, new genus 



Shell, small, elongate-turreted, nuclear whorls forming an acute 

 apex, consisting of about 2 strongly rounded, smooth whorls, which 

 are succeeded by a short stretch of moderately strong, retractively 

 curved, slender, axial riblets, which in turn give way to heavy post- 

 nuclear sculpture. The postnuclear whorls are angulated at or a 

 little anterior to the middle, and they are appressed at the summit 

 and marked by very strong sigmoid axial ribs, which taper toward 

 the summit and evanesce on the columella. The broad intercostal 

 spaces and the axial ribs are mai-ked by incremental lines and incised 

 spiral lines, the combination producing a somewhat fenestrated pat- 

 tern. Base rather long, bearing the same sculpture as the spire. 

 ColumeUa short, stubby, marked by irregular incremental lines. 



