176 BULUETES" 181, IMITEO SfTATEIS NlATTEOOSnAL MTJSlErUM 



that separate them. Suture slitlike on the last turn, separated from 

 the preceding turn by a considerably deeper channel on the last fifth 

 of a turn. Periphery well rounded. Base well rounded and marked 

 by the continuation of the oblique cords, which also extend over the 

 umbilical wall. Umbilicus about one-fourth the diameter of the 

 shell. Aperture circular; peristome somewhat thickened, heaviest on 

 the outer lip and thinnest on the columellar side. In the outer lip 

 the peristome projects over the wall of the parietal portion of the 

 peristome as an arch, which also projects forward considerably beyond 

 the parietal peristome. Operculum typical. 



The specimen described and figured, U.S.N.M. No. 523517, was 

 collected by H. Pittier in Costa Rica without specific definition of 

 locality. It has 6.1 whorls and measures : Height, 24.7 mm. ; greater 

 diameter, 41.7 mm. ; lesser diameter, 30.7 mm. 



Three additional specimens, U.S.N.M. No. 190287, were collected 

 by Pittier at Moin Hill, Costa Rica. 



The strong oblique threads that extend even over the last whorl in 

 this species readily differentiate it from the other two. 



BARBACYCLUS UNDERWOODI (Da Costa) 



Plate 23, Figures 7-9 



1900. Cyclophorus underwoodi Da Costa, Proc. Malac. Soc. London, vol. 4, p. 67, 



pi. 7, figs. 5-8. 

 1900. Cyclophorus (Amphicyclotns) undericoodi von Maetens, Biologia Cen- 



trali-Americana, Suppl., p. 598. 

 1902. Aniphicyclotus underwoodi Kobelt, Das Tierreich, Cyclophorldae, p. 257. 

 1912. Aniphicyclotus underwoodi Kobelt, Martini-Chemnitz Conchylien Cabinet, 



vol. 1, sect. 19, p. 919, pi. 135, figs. 2-A, 4a. 



Shell large, helicoid, of soiled-white ground color, with the early 

 whorls rose-red. The later whorls are marked also with a very dark 

 chestnut-brown band, which extends from a little below the suture 

 to a little above the periphery, and a second one much narrower 

 immediately below the periphery. The periphery in our specimens 

 is white. The base is orange straw-colored. Nuclear whorls about 2, 

 well rounded, smooth. The early postnuclear whorls are marked by 

 decidedly retractively curved almost spiral threads, which are about 

 as wide as the spaces that separate them. These threads disappear 

 on the last half of the last whorl. Suture of the early whorls well 

 impressed ; on the last, deeply channeled. The summit of the whorls 

 on the last half of the last turn projects over the parietal wall in 

 such a manner as to form a decided crest, which continues in an even 

 curve with the rest of the upper surface of the whorl toward the 

 preceding turn, leaving a broad exposed channel. Periphery well 

 rounded. Base well rounded. Umbilicus moderately large, a little 



