Hel. testa aperta-umbilicata, orbiculato depressa, alba, opaca, polita, minutissimo-oblique striata; anfractibus quatuor vel quinque convexis, ultimo magno antice deflexo; spira vix elevata, apice sub-mamillato; sutura modice impressa; apertura fere circulari; labro tenui, reflexiusculo, marginibus continuis ad juncturam; anfr. ultimo adnato.
Alt. ·4 pol., Diam. maj. ·6 pol., min. ·5 pol.
Hab. Arizona, (dicto Frick).
Shell with open umbilicus, orbicular, depressed, opaque white, polished, very finely obliquely striate; whorls four and a half, convex, the last large, anteriorly descending; spire but little elevated, at the apex projecting like a nipple; suture moderately marked; aperture truly circular; lip thin, slightly reflected, margins continued, adhering to the last whirl.
Remarks.—This is another of the Cyclostomoid species of which H. Carpenteri, Newc., H. Cærulano, Muhl., and H. Angasiana, Pfr. form striking examples. Our species approaches nearer in lightness of substance and in its depressed form to Muhlfeldt’s shell, than to either the others.
I take pleasure in dedicating this species to the Rev. M. Rowell, of San Francisco.
Succinea Japonica, Newc.
S. testa ovato-conica, flavido-cornea, lævissima, striatula, nitida, pellucida; anfractibus III, nucleo sane mamillato, ultimo 4·5 longitudinis fere æquante; apertura elongato-ovali; peristomate simplici; columellâ regulariter arcuata ad juncturam labro superiorem acuto-angulata.
Long. ·55, Diam. ·35, Apert. long. ·4, lata. ·233 pol.
Hab. Japan, (Prof. Blake).