THE CYCI^OPHO'RID LAND MOLLXJSfKS OF AMERICA 59 



AMPHICYCLOTULUS (AMPHICYCLOTULUS) PERPLEXUS, new species 



Plate 11, Figxjkes 7-9 



Shell small, depressed-helicoid, covered by a wax-yellow periostra- 

 cum, which assumes a rosy tinge toward the apex. Nuclear whorls 

 almost 2, well rounded, smooth. Postnuclear whorls inflated, strongly 

 rounded, marked by slender incremental lines and on the next to the 

 last turn by six low, rounded spiral threads, of which the one at the 

 summit is weaker than the rest. On the last whorl these threads be- 

 come obsolete and almost vanish before reaching the peristome. Su- 

 ture moderately impressed. Periphery well rounded. Base well 

 rounded, openly umbilicated, the umbilicus being about one-third the 

 width of the gi-eater diameter. The base is marked by incremental 

 lines only. Aperture slightly oblique, circular, with a slight angle 

 at the posterior angle; peristome simple. Operculum typically 

 amphicyclotulid. 



The type, U.S.N.M. No. 535858, comes from Guadeloupe. It has 

 4.9 whorls and measures: Height, 7.0 mm.; greater diameter, 11.5 

 mm. ; lesser diameter, 8.0 imn. 



U.S.N.M No. 43485 contains another specimen from the same lo- 

 cality. 



U.S.N.M. No. 151348a contains two additional specimens collected 

 by Salle on Guadeloupe. 



The weak sculpture of this species will differentiate it from the 

 rest of the species. 



AMPHICYCLOTULUS (AMPHICYCLOTULUS) PORTORICENSIS (Boettger) 



Plate 11, Figuees 19-21 



1887. Cyclotus portoricensis Boettgeb, Jahrb. deutschen malak. Ges., vol. 14, 

 pp. 101-102, pi. 4, fig. 7. 



Shell broadly openly umbilicated, umbilicus equaling a fifth part 

 of the width of the base, depressed-turbinate, solid, olivaceous, a little 

 lighter on the base, shining, spire little expanded, convex ; apex quite 

 small, somewhat obtuse, after decortication, red. Whorls, 5-5.5, in- 

 creasing regularly in size, with impressed disjunct suture, convex, 

 minutely rugulose striate and everywhere densely spirally lirate, lirae 

 13-15 in the penultimate whorl, last whorl terete, base more convex, 

 a little expanded at the aperture or slightly descending. Aperture 

 moderately large, oblique; peristome continuous, straight, acute, 

 white, with the margin somewhat thickened all around; columella a 

 little retracted and reflected. Operculum immersed, corneous with 

 11 turns, its nucleus concave. 



