8 PEOCEEDINGS OF THE NATIONAL. MUSEUM vol. 81 



Another narrow, very pale brown band is present immediately below 

 the periphery. The rest of the base and the peristome are white. 

 The dark bands show within the aperture. Nuclear whorls 1.3, low, 

 well rounded, marked by incremental lines and microscopic granula- 

 tions. The postnuclear whorls are slightly rounded and marked by 

 poorly defined retractively curved axial threads. These become a 

 little more pronounced toward the last part of the last turn. Suture 

 moderately impressed. The last whorl descends near the aperture to 

 considerably below the well-rounded periphery. The base is strongly, 

 evenly rounded, marked by a feeble continuation of the axial riblets 

 with the umbilicus completely closed. There is a strong pit imme- 

 diately below the periphery and a little distance behind the aperture, 

 which corresponds to the fold on the inside of the outer lip, which 

 extends halfway across the aperture. The aperture is oval with the 

 outer lip expanded, reflected, and decidedly thickened. There is a 

 strong fold on the middle of the basal wall. The parietal wall is 

 covered by a thick callus, which has a sigmoid outline on its left 

 border. 



Type.—ThQ type, U.S.N.M. No. 403910, measures: Height, 13.1 

 mm ; greater diameter, 21.4 mm ; lesser diameter, 16.2 mm. 



Remarks. — U.S.N.M. No. 403911 contains another bleached speci- 

 men. 



This subspecies is distinguished from Cepolis trizonalis in being 

 much smaller and in having the basal brown band much narrower. 

 It is distinguished from Cepolis trizonella by its closed umbilicus. 



PLAGIOPTYCHA (MONODONTA) BEATENSIS, new species 



Plate 3, Figures 7, 8, 9 



Shell small, subglobose, the early whorls flesh-colored, the last 

 three with interrupted spiral bands of brown. A continuous band 

 of brown is present a little posterior to the periphery, which in spite 

 of its continuity, shows circular areas, indicating spots, and between 

 this and the summit are two zones of brown spots. There is an- 

 other zone of small brown spots at the periphery and a second con- 

 tinuous band about as far anterior to the periphery as the other 

 continuous band is posterior to it. The base is marked by five zones 

 of round brown spots, which are arranged not only in spiral but in 

 axial series. Nuclear whorls 1.2, moderately well rounded, marked 

 by fine incremental lines and microscopic granulations. Postnuclear 

 whorls well rounded, separated by a moderately impressed suture, 

 marked by retractively slanting lines of growth. Periphery well 

 rounded. Base somewhat inflated, strongly rounded, marked by the 

 continuations of the lines of growth. The last whorl descends de- 



