REMARKS.—Mr. Bland may _possibly_ refer to this species as _H. striatella_, Anthony, which was obtained by Dr. Cooper on the Pacific side of the Rocky Mountains. (See addenda to “Remarks on Classification, etc.,” 1863). This species is certainly distinct from _striatella_, by its smaller size, rib-like costa, and almost channelled suture. A few specimens were obtained by Mr. Gabb, of the State Geological Survey, in Klamath Valley, which were collected jointly by himself and Dr. Cronkhite, U. S. Army. _Helix Rowelli_, Newc. 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). Shell ovately-conic, yellowish horn color, very smooth, finely striate, shining, pellucid; whirls three, nucleus truly mamillate, the last four-fifths of the entire length; aperture elongately ovate; lip simple; columella regularly arched; at the juncture of the lip above, acutely angular. _Remarks on Helix Hillebrandi_, Newc.