TUB CYCIxOPHORI'D LAND MOLLUSKS OF AMERICA 153 



incremental lines. Between the suture and the first strong keel, a 

 little nearer to the latter, there is another spiral thread on the dorsal 

 surface, which is materially stronger than the fine spiral hairlines cov- 

 ering the rest of the whorl in this region. Of these fine spiral hair- 

 lines, 19 are present between the suture and the stronger thread 

 and 17 between that and the first strong keel, in the specimen which 

 we are figuring. On the ventral side there is also a median stronger 

 thread corresponding to one on the upper side and between this 

 and the suture 19 spiral hairlines are present, while the space be- 

 tween this and the first strong keel bears 15 spiral hairlines. The 

 suture is strongly channeled on both the upper and the lower surface, 

 and shows the spiral keel. Aperture circular; peristome simple, 

 rendered fluted on the peripheral side. Operculum with central 

 nucleus, many whorls with the outer edge of the later whorls up- 

 turned and projecting as flakelike elements. 



The specimen described and figured, U.S.N.M. No. 420868, bears 

 the locality label "Ecuador." It has 4.5 whorls and measures : Height, 

 7.5 mm. ; greater diameter, 24.7 mm. ; lesser diameter, 17.9 mm. 



The four strong keels readily differentiate this from the other spe- 

 cies here discussed. 



BUCKLEYIA BIFASCIATA Monsson 

 PIATE3 19, FlGTTRES 16-18 



1873. Buckleya Mfiasciata Mousson, Malak. Blatter, vol. 21, p. 17. 



1875. Buckleya bifasciata Pfeiffer, Nov. Conch., vol. 4, p. 132, pi. 129, figs. 15-18. 



1876. Cyclophorus hifasciata Pfeiffek, Monographia pneumonopomorum viven- 



tiurn, vol. 4, p. 122. 

 1897. Buckleyia bifasciata Kobelt and Mollendobff, Nachrb. deutschen malak. 

 Ges., vol. 29, p. 139. 



Shell disk shaped, concave on both the upper and lower surface, 

 of olivaceous ground color, marked with darker spiral zones of vary- 

 ing width. There are two broad paler bands at some little distance 

 above and below the periphery, which are edged with darker zones, 

 which consist of a series of interrupted elongated beadlike elements. 

 The ground color is not uniform but has a marbled effect. The 

 nuclear whorls consist of a smooth fraction of a turn followed by a por- 

 tion bearing spiral hairlines and this in turn is succeeded by whorls that 

 have 4 low rounded cords (not keels), the space between the two 

 central ones being wider than that which separates the two adjacent 

 to these. The central ones are equally distant from the periphery. 

 Between the central ones 8 spiral threads are present, while between 

 the two cords on the dorsal surface 5 spiral threads are present. 

 The rest of the dorsal surface also bears spiral threads, of which 

 13 are present on the anterior half of the turns, while on the pos- 



